summaryrefslogtreecommitdiffstats
path: root/src/3rdparty/libpng/CHANGES
blob: 628d7f04533fac5c9e683a487d1f7cba3aeac2e1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
#if 0
libpng_changes(){ /*
CHANGES - changes for libpng

Version 0.2
  added reader into png.h
  fixed small problems in stub file

Version 0.3
  added pull reader
  split up pngwrite.c to several files
  added pnglib.txt
  added example.c
  cleaned up writer, adding a few new transformations
  fixed some bugs in writer
  interfaced with zlib 0.5
  added K&R support
  added check for 64 KB blocks for 16-bit machines

Version 0.4
  cleaned up code and commented code
  simplified time handling into png_time
  created png_color_16 and png_color_8 to handle color needs
  cleaned up color type defines
  fixed various bugs
  made various names more consistent
  interfaced with zlib 0.71
  cleaned up zTXt reader and writer (using zlib's Reset functions)
  split transformations into pngrtran.c and pngwtran.c

Version 0.5
  interfaced with zlib 0.8
  fixed many reading and writing bugs
  saved using 3 spaces instead of tabs

Version 0.6
  added png_large_malloc() and png_large_free()
  added png_size_t
  cleaned up some compiler warnings
  added png_start_read_image()

Version 0.7
  cleaned up lots of bugs
  finished dithering and other stuff
  added test program
  changed name from pnglib to libpng

Version 0.71 [June, 1995]
  changed pngtest.png for zlib 0.93
  fixed error in libpng.txt and example.c

Version 0.8
  cleaned up some bugs
  added png_set_filler()
  split up pngstub.c into pngmem.c, pngio.c, and pngerror.c
  added #define's to remove unwanted code
  moved png_info_init() to png.c
  added old_size into png_realloc()
  added functions to manually set filtering and compression info
  changed compression parameters based on image type
  optimized filter selection code
  added version info
  changed external functions passing floats to doubles (k&r problems?)
  put all the configurable stuff in pngconf.h
  enabled png_set_shift to work with paletted images on read
  added png_read_update_info() - updates info structure with transformations

Version 0.81 [August, 1995]
  incorporated Tim Wegner's medium model code (thanks, Tim)

Version 0.82 [September, 1995]
  [unspecified changes]

Version 0.85 [December, 1995]
  added more medium model code (almost everything's a far)
  added i/o, error, and memory callback functions
  fixed some bugs (16-bit, 4-bit interlaced, etc.)
  added first run progressive reader (barely tested)

Version 0.86 [January, 1996]
  fixed bugs
  improved documentation

Version 0.87 [January, 1996]
  fixed medium model bugs
  fixed other bugs introduced in 0.85 and 0.86
  added some minor documentation

Version 0.88 [January, 1996]
  fixed progressive bugs
  replaced tabs with spaces
  cleaned up documentation
  added callbacks for read/write and warning/error functions

Version 0.89 [July, 1996]
  Added new initialization API to make libpng work better with shared libs
    we now have png_create_read_struct(), png_create_write_struct(),
    png_create_info_struct(), png_destroy_read_struct(), and
    png_destroy_write_struct() instead of the separate calls to
    malloc and png_read_init(), png_info_init(), and png_write_init()
  Changed warning/error callback functions to fix bug - this means you
    should use the new initialization API if you were using the old
    png_set_message_fn() calls, and that the old API no longer exists
    so that people are aware that they need to change their code
  Changed filter selection API to allow selection of multiple filters
    since it didn't work in previous versions of libpng anyways
  Optimized filter selection code
  Fixed png_set_background() to allow using an arbitrary RGB color for
    paletted images
  Fixed gamma and background correction for paletted images, so
    png_correct_palette is not needed unless you are correcting an
    external palette (you will need to #define PNG_CORRECT_PALETTE_SUPPORTED
    in pngconf.h) - if nobody uses this, it may disappear in the future.
  Fixed bug with Borland 64K memory allocation (Alexander Lehmann)
  Fixed bug in interlace handling (Smarasderagd, I think)
  Added more error checking for writing and image to reduce invalid files
  Separated read and write functions so that they won't both be linked
    into a binary when only reading or writing functionality is used
  New pngtest image also has interlacing and zTXt
  Updated documentation to reflect new API

Version 0.90 [January, 1997]
  Made CRC errors/warnings on critical and ancillary chunks configurable
  libpng will use the zlib CRC routines by (compile-time) default
  Changed DOS small/medium model memory support - needs zlib 1.04 (Tim Wegner)
  Added external C++ wrapper statements to png.h (Gilles Dauphin)
  Allow PNG file to be read when some or all of file signature has already
    been read from the beginning of the stream.  ****This affects the size
    of info_struct and invalidates all programs that use a shared libpng****
  Fixed png_filler() declarations
  Fixed? background color conversions
  Fixed order of error function pointers to match documentation
  Current chunk name is now available in png_struct to reduce the number
    of nearly identical error messages (will simplify multi-lingual
    support when available)
  Try to get ready for unknown-chunk callback functions:
    - previously read critical chunks are flagged, so the chunk handling
      routines can determine if the chunk is in the right place
    - all chunk handling routines have the same prototypes, so we will
      be able to handle all chunks via a callback mechanism
  Try to fix Linux "setjmp" buffer size problems
  Removed png_large_malloc, png_large_free, and png_realloc functions.

Version 0.95 [March, 1997]
  Fixed bug in pngwutil.c allocating "up_row" twice and "avg_row" never
  Fixed bug in PNG file signature compares when start != 0
  Changed parameter type of png_set_filler(...filler...) from png_byte
    to png_uint_32
  Added test for MACOS to ensure that both math.h and fp.h are not #included
  Added macros for libpng to be compiled as a Windows DLL (Andreas Kupries)
  Added "packswap" transformation, which changes the endianness of
    packed-pixel bytes (Kevin Bracey)
  Added "strip_alpha" transformation, which removes the alpha channel of
    input images without using it (not necessarily a good idea)
  Added "swap_alpha" transformation, which puts the alpha channel in front
    of the color bytes instead of after
  Removed all implicit variable tests which assume NULL == 0 (I think)
  Changed several variables to "png_size_t" to show 16/32-bit limitations
  Added new pCAL chunk read/write support
  Added experimental filter selection weighting (Greg Roelofs)
  Removed old png_set_rgbx() and png_set_xrgb() functions that have been
     obsolete for about 2 years now (use png_set_filler() instead)
  Added macros to read 16- and 32-bit ints directly from buffer, to be
    used only on those systems that support it (namely PowerPC and 680x0)
    With some testing, this may become the default for MACOS/PPC systems.
  Only calculate CRC on data if we are going to use it
  Added macros for zTXt compression type PNG_zTXt_COMPRESSION_???
  Added macros for simple libpng debugging output selectable at compile time
  Removed PNG_READ_END_MODE in progressive reader (Smarasderagd)
  More description of info_struct in libpng.txt and png.h
  More instructions in example.c
  More chunk types tested in pngtest.c
  Renamed pngrcb.c to pngset.c, and all png_read_<chunk> functions to be
    png_set_<chunk>.  We now have corresponding png_get_<chunk>
    functions in pngget.c to get information in info_ptr.  This isolates
    the application from the internal organization of png_info_struct
    (good for shared library implementations).

Version 0.96 [May, 1997]
  Fixed serious bug with < 8bpp images introduced in 0.95
  Fixed 256-color transparency bug (Greg Roelofs)
  Fixed up documentation (Greg Roelofs, Laszlo Nyul)
  Fixed "error" in pngconf.h for Linux setjmp() behaviour
  Fixed DOS medium model support (Tim Wegner)
  Fixed png_check_keyword() for case with error in static string text
  Added read of CRC after IEND chunk for embedded PNGs (Laszlo Nyul)
  Added typecasts to quiet compiler errors
  Added more debugging info

Version 0.97 [January, 1998]
  Removed PNG_USE_OWN_CRC capability
  Relocated png_set_crc_action from pngrutil.c to pngrtran.c
  Fixed typecasts of "new_key", etc. (Andreas Dilger)
  Added RFC 1152 [sic] date support
  Fixed bug in gamma handling of 4-bit grayscale
  Added 2-bit grayscale gamma handling (Glenn R-P)
  Added more typecasts. 65536L becomes (png_uint_32)65536L, etc. (Glenn R-P)
  Minor corrections in libpng.txt
  Added simple sRGB support (Glenn R-P)
  Easier conditional compiling, e.g. define PNG_READ/WRITE_NOT_FULLY_SUPPORTED;
    all configurable options can be selected from command-line instead
    of having to edit pngconf.h (Glenn R-P)
  Fixed memory leak in pngwrite.c (free info_ptr->text) (Glenn R-P)
  Added more conditions for png_do_background, to avoid changing
    black pixels to background when a background is supplied and
    no pixels are transparent
  Repaired PNG_NO_STDIO behaviour
  Tested NODIV support and made it default behaviour (Greg Roelofs)
  Added "-m" option and PNGTEST_DEBUG_MEMORY to pngtest (John Bowler)
  Regularized version numbering scheme and bumped shared-library major
     version number to 2 to avoid problems with libpng 0.89 apps (Greg Roelofs)

Version 0.98 [January, 1998]
  Cleaned up some typos in libpng.txt and in code documentation
  Fixed memory leaks in pCAL chunk processing (Glenn R-P and John Bowler)
  Cosmetic change "display_gamma" to "screen_gamma" in pngrtran.c
  Changed recommendation about file_gamma for PC images to .51 from .45,
    in example.c and libpng.txt, added comments to distinguish between
    screen_gamma, viewing_gamma, and display_gamma.
  Changed all references to RFC1152 to read RFC1123 and changed the
    PNG_TIME_RFC1152_SUPPORTED macro to PNG_TIME_RFC1123_SUPPORTED
  Added png_invert_alpha capability (Glenn R-P -- suggestion by Jon Vincent)
  Changed srgb_intent from png_byte to int to avoid compiler bugs

Version 0.99 [January 30, 1998]
  Free info_ptr->text instead of end_info_ptr->text in pngread.c (John Bowler)
  Fixed a longstanding "packswap" bug in pngtrans.c
  Fixed some inconsistencies in pngconf.h that prevented compiling with
    PNG_READ_GAMMA_SUPPORTED and PNG_READ_hIST_SUPPORTED undefined
  Fixed some typos and made other minor rearrangement of libpng.txt (Andreas)
  Changed recommendation about file_gamma for PC images to .50 from .51 in
    example.c and libpng.txt, and changed file_gamma for sRGB images to .45
  Added a number of functions to access information from the png structure
    png_get_image_height(), etc. (Glenn R-P, suggestion by Brad Pettit)
  Added TARGET_MACOS similar to zlib-1.0.8
  Define PNG_ALWAYS_EXTERN when __MWERKS__ && WIN32 are defined
  Added type casting to all png_malloc() function calls

Version 0.99a [January 31, 1998]
  Added type casts and parentheses to all returns that return a value.(Tim W.)

Version 0.99b [February 4, 1998]
  Added type cast png_uint_32 on malloc function calls where needed.
  Changed type of num_hist from png_uint_32 to int (same as num_palette).
  Added checks for rowbytes overflow, in case png_size_t is less than 32 bits.
  Renamed makefile.elf to makefile.lnx.

Version 0.99c [February 7, 1998]
  More type casting.  Removed erroneous overflow test in pngmem.c.
  Added png_buffered_memcpy() and png_buffered_memset(), apply them to rowbytes.
  Added UNIX manual pages libpng.3 (incorporating libpng.txt) and  png.5.

Version 0.99d [February 11, 1998]
  Renamed "far_to_near()" "png_far_to_near()"
  Revised libpng.3
  Version 99c "buffered" operations didn't work as intended.  Replaced them
    with png_memcpy_check() and png_memset_check().
  Added many "if (png_ptr == NULL) return" to quell compiler warnings about
    unused png_ptr, mostly in pngget.c and pngset.c.
  Check for overlength tRNS chunk present when indexed-color PLTE is read.
  Cleaned up spelling errors in libpng.3/libpng.txt
  Corrected a problem with png_get_tRNS() which returned undefined trans array

Version 0.99e [February 28, 1998]
  Corrected png_get_tRNS() again.
  Add parentheses for easier reading of pngget.c, fixed "||" should be "&&".
  Touched up example.c to make more of it compileable, although the entire
    file still can't be compiled (Willem van Schaik)
  Fixed a bug in png_do_shift() (Bryan Tsai)
  Added a space in png.h prototype for png_write_chunk_start()
  Replaced pngtest.png with one created with zlib 1.1.1
  Changed pngtest to report PASS even when file size is different (Jean-loup G.)
  Corrected some logic errors in png_do_invert_alpha() (Chris Patterson)

Version 0.99f [March 5, 1998]
  Corrected a bug in pngpread() introduced in version 99c (Kevin Bracey)
  Moved makefiles into a "scripts" directory, and added INSTALL instruction file
  Added makefile.os2 and pngos2.def (A. Zabolotny) and makefile.s2x (W. Sebok)
  Added pointers to "note on libpng versions" in makefile.lnx and README
  Added row callback feature when reading and writing nonprogressive rows
    and added a test of this feature in pngtest.c
  Added user transform callbacks, with test of the feature in pngtest.c

Version 0.99g [March 6, 1998, morning]
  Minor changes to pngtest.c to suppress compiler warnings.
  Removed "beta" language from documentation.

Version 0.99h [March 6, 1998, evening]
  Minor changes to previous minor changes to pngtest.c
  Changed PNG_READ_NOT_FULLY_SUPPORTED to PNG_READ_TRANSFORMS_NOT_SUPPORTED
    and added PNG_PROGRESSIVE_READ_NOT_SUPPORTED macro
  Added user transform capability

Version 1.00 [March 7, 1998]
  Changed several typedefs in pngrutil.c
  Added makefile.wat (Pawel Mrochen), updated makefile.tc3 (Willem van Schaik)
  Replaced "while(1)" with "for(;;)"
  Added PNGARG() to prototypes in pngtest.c and removed some prototypes
  Updated some of the makefiles (Tom Lane)
  Changed some typedefs (s_start, etc.) in pngrutil.c
  Fixed dimensions of "short_months" array in pngwrite.c
  Replaced ansi2knr.c with the one from jpeg-v6

Version 1.0.0 [March 8, 1998]
  Changed name from 1.00 to 1.0.0 (Adam Costello)
  Added smakefile.ppc (with SCOPTIONS.ppc) for Amiga PPC (Andreas Kleinert)

Version 1.0.0a [March 9, 1998]
  Fixed three bugs in pngrtran.c to make gamma+background handling consistent
    (Greg Roelofs)
  Changed format of the PNG_LIBPNG_VER integer to xyyzz instead of xyz
    for major, minor, and bugfix releases.  This is 10001. (Adam Costello,
    Tom Lane)
  Make months range from 1-12 in png_convert_to_rfc1123

Version 1.0.0b [March 13, 1998]
  Quieted compiler complaints about two empty "for" loops in pngrutil.c
  Minor changes to makefile.s2x
  Removed #ifdef/#endif around a png_free() in pngread.c

Version 1.0.1 [March 14, 1998]
  Changed makefile.s2x to reduce security risk of using a relative pathname
  Fixed some typos in the documentation (Greg).
  Fixed a problem with value of "channels" returned by png_read_update_info()

Version 1.0.1a [April 21, 1998]
  Optimized Paeth calculations by replacing abs() function calls with intrinsics
  plus other loop optimizations. Improves avg decoding speed by about 20%.
  Commented out i386istic "align" compiler flags in makefile.lnx.
  Reduced the default warning level in some makefiles, to make them consistent.
  Removed references to IJG and JPEG in the ansi2knr.c copyright statement.
  Fixed a bug in png_do_strip_filler with XXRRGGBB => RRGGBB transformation.
  Added grayscale and 16-bit capability to png_do_read_filler().
  Fixed a bug in pngset.c, introduced in version 0.99c, that sets rowbytes
    too large when writing an image with bit_depth < 8 (Bob Dellaca).
  Corrected some bugs in the experimental weighted filtering heuristics.
  Moved a misplaced pngrutil code block that truncates tRNS if it has more
    than num_palette entries -- test was done before num_palette was defined.
  Fixed a png_convert_to_rfc1123() bug that converts day 31 to 0 (Steve Eddins).
  Changed compiler flags in makefile.wat for better optimization
    (Pawel Mrochen).

Version 1.0.1b [May 2, 1998]
  Relocated png_do_gray_to_rgb() within png_do_read_transformations() (Greg).
  Relocated the png_composite macros from pngrtran.c to png.h (Greg).
  Added makefile.sco (contributed by Mike Hopkirk).
  Fixed two bugs (missing definitions of "istop") introduced in libpng-1.0.1a.
  Fixed a bug in pngrtran.c that would set channels=5 under some circumstances.
  More work on the Paeth-filtering, achieving imperceptible speedup
    (A Kleinert).
  More work on loop optimization which may help when compiled with C++
    compilers.
  Added warnings when people try to use transforms they've defined out.
  Collapsed 4 "i" and "c" loops into single "i" loops in pngrtran and pngwtran.
  Revised paragraph about png_set_expand() in libpng.txt and libpng.3 (Greg)

Version 1.0.1c [May 11, 1998]
  Fixed a bug in pngrtran.c (introduced in libpng-1.0.1a) where the masks for
    filler bytes should have been 0xff instead of 0xf.
  Added max_pixel_depth=32 in pngrutil.c when using FILLER with palette images.
  Moved PNG_WRITE_WEIGHTED_FILTER_SUPPORTED and PNG_WRITE_FLUSH_SUPPORTED
    out of the PNG_WRITE_TRANSFORMS_NOT_SUPPORTED block of pngconf.h
  Added "PNG_NO_WRITE_TRANSFORMS" etc., as alternatives for *_NOT_SUPPORTED,
    for consistency, in pngconf.h
  Added individual "ifndef PNG_NO_[CAPABILITY]" in pngconf.h to make it easier
    to remove unwanted capabilities via the compile line
  Made some corrections to grammar (which, it's) in documentation (Greg).
  Corrected example.c, use of row_pointers in png_write_image().

Version 1.0.1d [May 24, 1998]
  Corrected several statements that used side effects illegally in pngrutil.c
    and pngtrans.c, that were introduced in version 1.0.1b
  Revised png_read_rows() to avoid repeated if-testing for NULL (A Kleinert)
  More corrections to example.c, use of row_pointers in png_write_image()
    and png_read_rows().
  Added pngdll.mak and pngdef.pas to scripts directory, contributed by
    Bob Dellaca, to make a png32bd.dll with Borland C++ 4.5
  Fixed error in example.c with png_set_text: num_text is 3, not 2 (Guido V.)
  Changed several loops from count-down to count-up, for consistency.

Version 1.0.1e [June 6, 1998]
  Revised libpng.txt and libpng.3 description of png_set_read|write_fn(), and
    added warnings when people try to set png_read_fn and png_write_fn in
    the same structure.
  Added a test such that png_do_gamma will be done when num_trans==0
    for truecolor images that have defined a background.  This corrects an
    error that was introduced in libpng-0.90 that can cause gamma processing
    to be skipped.
  Added tests in png.h to include "trans" and "trans_values" in structures
    when PNG_READ_BACKGROUND_SUPPORTED or PNG_READ_EXPAND_SUPPORTED is defined.
  Add png_free(png_ptr->time_buffer) in png_destroy_read_struct()
  Moved png_convert_to_rfc_1123() from pngwrite.c to png.c
  Added capability for user-provided malloc_fn() and free_fn() functions,
    and revised pngtest.c to demonstrate their use, replacing the
    PNGTEST_DEBUG_MEM feature.
  Added makefile.w32, for Microsoft C++ 4.0 and later (Tim Wegner).

Version 1.0.2 [June 14, 1998]
  Fixed two bugs in makefile.bor .

Version 1.0.2a [December 30, 1998]
  Replaced and extended code that was removed from png_set_filler() in 1.0.1a.
  Fixed a bug in png_do_filler() that made it fail to write filler bytes in
    the left-most pixel of each row (Kevin Bracey).
  Changed "static pngcharp tIME_string" to "static char tIME_string[30]"
    in pngtest.c (Duncan Simpson).
  Fixed a bug in pngtest.c that caused pngtest to try to write a tIME chunk
    even when no tIME chunk was present in the source file.
  Fixed a problem in pngrutil.c: gray_to_rgb didn't always work with 16-bit.
  Fixed a problem in png_read_push_finish_row(), which would not skip some
    passes that it should skip, for images that are less than 3 pixels high.
  Interchanged the order of calls to png_do_swap() and png_do_shift()
    in pngwtran.c (John Cromer).
  Added #ifdef PNG_DEBUG/#endif surrounding use of PNG_DEBUG in png.h .
  Changed "bad adaptive filter type" from error to warning in pngrutil.c .
  Fixed a documentation error about default filtering with 8-bit indexed-color.
  Separated the PNG_NO_STDIO macro into PNG_NO_STDIO and PNG_NO_CONSOLE_IO
    (L. Peter Deutsch).
  Added png_set_rgb_to_gray() and png_get_rgb_to_gray_status() functions.
  Added png_get_copyright() and png_get_header_version() functions.
  Revised comments on png_set_progressive_read_fn() in libpng.txt and example.c
  Added information about debugging in libpng.txt and libpng.3 .
  Changed "ln -sf" to "ln -s -f" in makefile.s2x, makefile.lnx, and
    makefile.sco.
  Removed lines after Dynamic Dependencies" in makefile.aco .
  Revised makefile.dec to make a shared library (Jeremie Petit).
  Removed trailing blanks from all files.

Version 1.0.2a [January 6, 1999]
  Removed misplaced #endif and #ifdef PNG_NO_EXTERN near the end of png.h
  Added "if" tests to silence complaints about unused png_ptr in png.h and png.c
  Changed "check_if_png" function in example.c to return true (nonzero) if PNG.
  Changed libpng.txt to demonstrate png_sig_cmp() instead of png_check_sig()
    which is obsolete.

Version 1.0.3 [January 14, 1999]
  Added makefile.hux, for Hewlett Packard HPUX 10.20 and 11.00 (Jim Rice)
  Added a statement of Y2K compliance in png.h, libpng.3, and Y2KINFO.

Version 1.0.3a [August 12, 1999]
  Added check for PNG_READ_INTERLACE_SUPPORTED in pngread.c; issue a warning
     if an attempt is made to read an interlaced image when it's not supported.
  Added check if png_ptr->trans is defined before freeing it in pngread.c
  Modified the Y2K statement to include versions back to version 0.71
  Fixed a bug in the check for valid IHDR bit_depth/color_types in pngrutil.c
  Modified makefile.wat (added -zp8 flag, ".symbolic", changed some comments)
  Replaced leading blanks with tab characters in makefile.hux
  Changed "dworkin.wustl.edu" to "ccrc.wustl.edu" in various documents.
  Changed (float)red and (float)green to (double)red, (double)green
     in png_set_rgb_to_gray() to avoid "promotion" problems in AIX.
  Fixed a bug in pngconf.h that omitted <stdio.h> when PNG_DEBUG==0 (K Bracey).
  Reformatted libpng.3 and libpngpf.3 with proper fonts (script by J. vanZandt).
  Updated documentation to refer to the PNG-1.2 specification.
  Removed ansi2knr.c and left pointers to the latest source for ansi2knr.c
    in makefile.knr, INSTALL, and README (L. Peter Deutsch)
  Fixed bugs in calculation of the length of rowbytes when adding alpha
    channels to 16-bit images, in pngrtran.c (Chris Nokleberg)
  Added function png_set_user_transform_info() to store user_transform_ptr,
    user_depth, and user_channels into the png_struct, and a function
    png_get_user_transform_ptr() to retrieve the pointer (Chris Nokleberg)
  Added function png_set_empty_plte_permitted() to make libpng useable
    in MNG applications.
  Corrected the typedef for png_free_ptr in png.h (Jesse Jones).
  Correct gamma with srgb is 45455 instead of 45000 in pngrutil.c, to be
    consistent with PNG-1.2, and allow variance of 500 before complaining.
  Added assembler code contributed by Intel in file pngvcrd.c and modified
    makefile.w32 to use it (Nirav Chhatrapati, INTEL Corporation,
    Gilles Vollant)
  Changed "ln -s -f" to "ln -f -s" in the makefiles to make Solaris happy.
  Added some aliases for png_set_expand() in pngrtran.c, namely
    png_set_expand_PLTE(), png_set_expand_depth(), and png_set_expand_tRNS()
    (Greg Roelofs, in "PNG: The Definitive Guide").
  Added makefile.beo for BEOS on X86, contributed by Sander Stok.

Version 1.0.3b [August 26, 1999]
  Replaced 2147483647L several places with PNG_MAX_UINT macro, defined in png.h
  Changed leading blanks to tabs in all makefiles.
  Define PNG_USE_PNGVCRD in makefile.w32, to get MMX assembler code.
  Made alternate versions of  png_set_expand() in pngrtran.c, namely
    png_set_gray_1_2_4_to_8, png_set_palette_to_rgb, and png_set_tRNS_to_alpha
    (Greg Roelofs, in "PNG: The Definitive Guide").  Deleted the 1.0.3a aliases.
  Relocated start of 'extern "C"' block in png.h so it doesn't include pngconf.h
  Revised calculation of num_blocks in pngmem.c to avoid a potentially
    negative shift distance, whose results are undefined in the C language.
  Added a check in pngset.c to prevent writing multiple tIME chunks.
  Added a check in pngwrite.c to detect invalid small window_bits sizes.

Version 1.0.3d [September 4, 1999]
  Fixed type casting of igamma in pngrutil.c
  Added new png_expand functions to scripts/pngdef.pas and pngos2.def
  Added a demo read_user_transform_fn that examines the row filters in pngtest.c

Version 1.0.4 [September 24, 1999]
  Define PNG_ALWAYS_EXTERN in pngconf.h if __STDC__ is defined
  Delete #define PNG_INTERNAL and include "png.h" from pngasmrd.h
  Made several minor corrections to pngtest.c
  Renamed the makefiles with longer but more user friendly extensions.
  Copied the PNG copyright and license to a separate LICENSE file.
  Revised documentation, png.h, and example.c to remove reference to
    "viewing_gamma" which no longer appears in the PNG specification.
  Revised pngvcrd.c to use MMX code for interlacing only on the final pass.
  Updated pngvcrd.c to use the faster C filter algorithms from libpng-1.0.1a
  Split makefile.win32vc into two versions, makefile.vcawin32 (uses MMX
    assembler code) and makefile.vcwin32 (doesn't).
  Added a CPU timing report to pngtest.c (enabled by defining PNGTEST_TIMING)
  Added a copy of pngnow.png to the distribution.

Version 1.0.4a [September 25, 1999]
  Increase max_pixel_depth in pngrutil.c if a user transform needs it.
  Changed several division operations to right-shifts in pngvcrd.c

Version 1.0.4b [September 30, 1999]
  Added parentheses in line 3732 of pngvcrd.c
  Added a comment in makefile.linux warning about buggy -O3 in pgcc 2.95.1

Version 1.0.4c [October 1, 1999]
  Added a "png_check_version" function in png.c and pngtest.c that will generate
    a helpful compiler error if an old png.h is found in the search path.
  Changed type of png_user_transform_depth|channels from int to png_byte.

Version 1.0.4d [October 6, 1999]
  Changed 0.45 to 0.45455 in png_set_sRGB()
  Removed unused PLTE entries from pngnow.png
  Re-enabled some parts of pngvcrd.c (png_combine_row) that work properly.

Version 1.0.4e [October 10, 1999]
  Fixed sign error in pngvcrd.c (Greg Roelofs)
  Replaced some instances of memcpy with simple assignments in pngvcrd (GR-P)

Version 1.0.4f [October 15, 1999]
  Surrounded example.c code with #if 0 .. #endif to prevent people from
    inadvertently trying to compile it.
  Changed png_get_header_version() from a function to a macro in png.h
  Added type casting mostly in pngrtran.c and pngwtran.c
  Removed some pointless "ptr = NULL" in pngmem.c
  Added a "contrib" directory containing the source code from Greg's book.

Version 1.0.5 [October 15, 1999]
  Minor editing of the INSTALL and README files.

Version 1.0.5a [October 23, 1999]
  Added contrib/pngsuite and contrib/pngminus (Willem van Schaik)
  Fixed a typo in the png_set_sRGB() function call in example.c (Jan Nijtmans)
  Further optimization and bugfix of pngvcrd.c
  Revised pngset.c so that it does not allocate or free memory in the user's
    text_ptr structure.  Instead, it makes its own copy.
  Created separate write_end_info_struct in pngtest.c for a more severe test.
  Added code in pngwrite.c to free info_ptr->text[i].key to stop a memory leak.

Version 1.0.5b [November 23, 1999]
  Moved PNG_FLAG_HAVE_CHUNK_HEADER, PNG_FLAG_BACKGROUND_IS_GRAY and
    PNG_FLAG_WROTE_tIME from flags to mode.
  Added png_write_info_before_PLTE() function.
  Fixed some typecasting in contrib/gregbook/*.c
  Updated scripts/makevms.com and added makevms.com to contrib/gregbook
    and contrib/pngminus (Martin Zinser)

Version 1.0.5c [November 26, 1999]
  Moved png_get_header_version from png.h to png.c, to accommodate ansi2knr.
  Removed all global arrays (according to PNG_NO_GLOBAL_ARRAYS macro), to
    accommodate making DLL's: Moved usr_png_ver from global variable to function
    png_get_header_ver() in png.c.  Moved png_sig to png_sig_bytes in png.c and
    eliminated use of png_sig in pngwutil.c.  Moved the various png_CHNK arrays
    into pngtypes.h.  Eliminated use of global png_pass arrays.  Declared the
    png_CHNK and png_pass arrays to be "const".  Made the global arrays
    available to applications (although none are used in libpng itself) when
    PNG_NO_GLOBAL_ARRAYS is not defined or when PNG_GLOBAL_ARRAYS is defined.
  Removed some extraneous "-I" from contrib/pngminus/makefile.std
  Changed the PNG_sRGB_INTENT macros in png.h to be consistent with PNG-1.2.
  Change PNG_SRGB_INTENT to PNG_sRGB_INTENT in libpng.txt and libpng.3

Version 1.0.5d [November 29, 1999]
  Add type cast (png_const_charp) two places in png.c
  Eliminated pngtypes.h; use macros instead to declare PNG_CHNK arrays.
  Renamed "PNG_GLOBAL_ARRAYS" to "PNG_USE_GLOBAL_ARRAYS" and made available
    to applications a macro "PNG_USE_LOCAL_ARRAYS".
  comment out (with #ifdef) all the new declarations when
    PNG_USE_GLOBAL_ARRAYS is defined.
  Added PNG_EXPORT_VAR macro to accommodate making DLL's.

Version 1.0.5e [November 30, 1999]
  Added iCCP, iTXt, and sPLT support; added "lang" member to the png_text
    structure; refactored the inflate/deflate support to make adding new chunks
    with trailing compressed parts easier in the future, and added new functions
    png_free_iCCP, png_free_pCAL, png_free_sPLT, png_free_text, png_get_iCCP,
    png_get_spalettes, png_set_iCCP, png_set_spalettes (Eric S. Raymond).
  NOTE: Applications that write text chunks MUST define png_text->lang
    before calling png_set_text(). It must be set to NULL if you want to
    write tEXt or zTXt chunks.  If you want your application to be able to
    run with older versions of libpng, use

      #ifdef PNG_iTXt_SUPPORTED
         png_text[i].lang = NULL;
      #endif

  Changed png_get_oFFs() and png_set_oFFs() to use signed rather than unsigned
    offsets (Eric S. Raymond).
  Combined PNG_READ_cHNK_SUPPORTED and PNG_WRITE_cHNK_SUPPORTED macros into
    PNG_cHNK_SUPPORTED and combined the three types of PNG_text_SUPPORTED
    macros, leaving the separate macros also available.
  Removed comments on #endifs at the end of many short, non-nested #if-blocks.

Version 1.0.5f [December 6, 1999]
  Changed makefile.solaris to issue a warning about potential problems when
    the ucb "ld" is in the path ahead of the ccs "ld".
  Removed "- [date]" from the "synopsis" line in libpng.3 and libpngpf.3.
  Added sCAL chunk support (Eric S. Raymond).

Version 1.0.5g [December 7, 1999]
  Fixed "png_free_spallettes" typo in png.h
  Added code to handle new chunks in pngpread.c
  Moved PNG_CHNK string macro definitions outside of PNG_NO_EXTERN block
  Added "translated_key" to png_text structure and png_write_iTXt().
  Added code in pngwrite.c to work around a newly discovered zlib bug.

Version 1.0.5h [December 10, 1999]
  NOTE: regarding the note for version 1.0.5e, the following must also
    be included in your code:
        png_text[i].translated_key = NULL;
  Unknown chunk handling is now supported.
  Option to eliminate all floating point support was added.  Some new
    fixed-point functions such as png_set_gAMA_fixed() were added.
  Expanded tabs and removed trailing blanks in source files.

Version 1.0.5i [December 13, 1999]
  Added some type casts to silence compiler warnings.
  Renamed "png_free_spalette" to "png_free_spalettes" for consistency.
  Removed leading blanks from a #define in pngvcrd.c
  Added some parameters to the new png_set_keep_unknown_chunks() function.
  Added a test for up->location != 0 in the first instance of writing
    unknown chunks in pngwrite.c
  Changed "num" to "i" in png_free_spalettes() and png_free_unknowns() to
    prevent recursion.
  Added png_free_hIST() function.
  Various patches to fix bugs in the sCAL and integer cHRM processing,
    and to add some convenience macros for use with sCAL.

Version 1.0.5j [December 21, 1999]
  Changed "unit" parameter of png_write_sCAL from png_byte to int, to work
    around buggy compilers.
  Added new type "png_fixed_point" for integers that hold float*100000 values
  Restored backward compatibility of tEXt/zTXt chunk processing:
    Restored the first four members of png_text to the same order as v.1.0.5d.
    Added members "lang_key" and "itxt_length" to png_text struct.  Set
    text_length=0 when "text" contains iTXt data.  Use the "compression"
    member to distinguish among tEXt/zTXt/iTXt types.  Added
    PNG_ITXT_COMPRESSION_NONE (1) and PNG_ITXT_COMPRESSION_zTXt(2) macros.
    The "Note" above, about backward incompatibility of libpng-1.0.5e, no
    longer applies.
  Fixed png_read|write_iTXt() to read|write parameters in the right order,
    and to write the iTXt chunk after IDAT if it appears in the end_ptr.
  Added pnggccrd.c, version of pngvcrd.c Intel assembler for gcc (Greg Roelofs)
  Reversed the order of trying to write floating-point and fixed-point gAMA.

Version 1.0.5k [December 27, 1999]
  Added many parentheses, e.g., "if (a && b & c)" becomes "if (a && (b & c))"
  Added png_handle_as_unknown() function (Glenn)
  Added png_free_chunk_list() function and chunk_list and num_chunk_list members
    of png_ptr.
  Eliminated erroneous warnings about multiple sPLT chunks and sPLT-after-PLTE.
  Fixed a libpng-1.0.5h bug in pngrutil.c that was issuing erroneous warnings
    about ignoring incorrect gAMA with sRGB (gAMA was in fact not ignored)
  Added png_free_tRNS(); png_set_tRNS() now malloc's its own trans array (ESR).
  Define png_get_int_32 when oFFs chunk is supported as well as when pCAL is.
  Changed type of proflen from png_int_32 to png_uint_32 in png_get_iCCP().

Version 1.0.5l [January 1, 2000]
  Added functions png_set_read_user_chunk_fn() and png_get_user_chunk_ptr()
    for setting a callback function to handle unknown chunks and for
    retrieving the associated user pointer (Glenn).

Version 1.0.5m [January 7, 2000]
  Added high-level functions png_read_png(), png_write_png(), png_free_pixels().

Version 1.0.5n [January 9, 2000]
  Added png_free_PLTE() function, and modified png_set_PLTE() to malloc its
    own memory for info_ptr->palette.  This makes it safe for the calling
    application to free its copy of the palette any time after it calls
    png_set_PLTE().

Version 1.0.5o [January 20, 2000]
  Cosmetic changes only (removed some trailing blanks and TABs)

Version 1.0.5p [January 31, 2000]
  Renamed pngdll.mak to makefile.bd32
  Cosmetic changes in pngtest.c

Version 1.0.5q [February 5, 2000]
  Relocated the makefile.solaris warning about PATH problems.
  Fixed pngvcrd.c bug by pushing/popping registers in mmxsupport (Bruce Oberg)
  Revised makefile.gcmmx
  Added PNG_SETJMP_SUPPORTED, PNG_SETJMP_NOT_SUPPORTED, and PNG_ABORT() macros

Version 1.0.5r [February 7, 2000]
  Removed superfluous prototype for png_get_itxt from png.h
  Fixed a bug in pngrtran.c that improperly expanded the background color.
  Return *num_text=0 from png_get_text() when appropriate, and fix documentation
    of png_get_text() in libpng.txt/libpng.3.

Version 1.0.5s [February 18, 2000]
  Added "png_jmp_env()" macro to pngconf.h, to help people migrate to the
    new error handler that's planned for the next libpng release, and changed
    example.c, pngtest.c, and contrib programs to use this macro.
  Revised some of the DLL-export macros in pngconf.h (Greg Roelofs)
  Fixed a bug in png_read_png() that caused it to fail to expand some images
    that it should have expanded.
  Fixed some mistakes in the unused and undocumented INCH_CONVERSIONS functions
    in pngget.c
  Changed the allocation of palette, history, and trans arrays back to
    the version 1.0.5 method (linking instead of copying) which restores
    backward compatibility with version 1.0.5.  Added some remarks about
    that in example.c.  Added "free_me" member to info_ptr and png_ptr
    and added png_free_data() function.
  Updated makefile.linux and makefile.gccmmx to make directories conditionally.
  Made cosmetic changes to pngasmrd.h
  Added png_set_rows() and png_get_rows(), for use with png_read|write_png().
  Modified png_read_png() to allocate info_ptr->row_pointers only if it
    hasn't already been allocated.

Version 1.0.5t [March 4, 2000]
  Changed png_jmp_env() migration aiding macro to png_jmpbuf().
  Fixed "interlace" typo (should be "interlaced") in contrib/gregbook/read2-x.c
  Fixed bug with use of PNG_BEFORE_IHDR bit in png_ptr->mode, introduced when
    PNG_FLAG_HAVE_CHUNK_HEADER was moved into png_ptr->mode in version 1.0.5b
  Files in contrib/gregbook were revised to use png_jmpbuf() and to select
    a 24-bit visual if one is available, and to allow abbreviated options.
  Files in contrib/pngminus were revised to use the png_jmpbuf() macro.
  Removed spaces in makefile.linux and makefile.gcmmx, introduced in 1.0.5s

Version 1.0.5u [March 5, 2000]
  Simplified the code that detects old png.h in png.c and pngtest.c
  Renamed png_spalette (_p, _pp) to png_sPLT_t (_tp, _tpp)
  Increased precision of rgb_to_gray calculations from 8 to 15 bits and
    added png_set_rgb_to_gray_fixed() function.
  Added makefile.bc32 (32-bit Borland C++, C mode)

Version 1.0.5v [March 11, 2000]
  Added some parentheses to the png_jmpbuf macro definition.
  Updated references to the zlib home page, which has moved to freesoftware.com.
  Corrected bugs in documentation regarding png_read_row() and png_write_row().
  Updated documentation of png_rgb_to_gray calculations in libpng.3/libpng.txt.
  Renamed makefile.borland,turboc3 back to makefile.bor,tc3 as in version 1.0.3,
    revised borland makefiles; added makefile.ibmvac3 and makefile.gcc (Cosmin)

Version 1.0.6 [March 20, 2000]
  Minor revisions of makefile.bor, libpng.txt, and gregbook/rpng2-win.c
  Added makefile.sggcc (SGI IRIX with gcc)

Version 1.0.6d [April 7, 2000]
  Changed sprintf() to strcpy() in png_write_sCAL_s() to work without STDIO
  Added data_length parameter to png_decompress_chunk() function
  Revised documentation to remove reference to abandoned png_free_chnk functions
  Fixed an error in png_rgb_to_gray_fixed()
  Revised example.c, usage of png_destroy_write_struct().
  Renamed makefile.ibmvac3 to makefile.ibmc, added libpng.icc IBM project file
  Added a check for info_ptr->free_me&PNG_FREE_TEXT when freeing text in png.c
  Simplify png_sig_bytes() function to remove use of non-ISO-C strdup().

Version 1.0.6e [April 9, 2000]
  Added png_data_freer() function.
  In the code that checks for over-length tRNS chunks, added check of
    info_ptr->num_trans as well as png_ptr->num_trans (Matthias Benckmann)
  Minor revisions of libpng.txt/libpng.3.
  Check for existing data and free it if the free_me flag is set, in png_set_*()
    and png_handle_*().
  Only define PNG_WEIGHTED_FILTERS_SUPPORTED when PNG_FLOATING_POINT_SUPPORTED
    is defined.
  Changed several instances of PNG_NO_CONSOLE_ID to PNG_NO_STDIO in pngrutil.c
    and mentioned the purposes of the two macros in libpng.txt/libpng.3.

Version 1.0.6f [April 14, 2000]
  Revised png_set_iCCP() and png_set_rows() to avoid prematurely freeing data.
  Add checks in png_set_text() for NULL members of the input text structure.
  Revised libpng.txt/libpng.3.
  Removed superfluous prototype for png_set_iTXt from png.h
  Removed "else" from pngread.c, after png_error(), and changed "0" to "length".
  Changed several png_errors about malformed ancillary chunks to png_warnings.

Version 1.0.6g [April 24, 2000]
  Added png_pass-* arrays to pnggccrd.c when PNG_USE_LOCAL_ARRAYS is defined.
  Relocated paragraph about png_set_background() in libpng.3/libpng.txt
    and other revisions (Matthias Benckmann)
  Relocated info_ptr->free_me, png_ptr->free_me, and other info_ptr and
    png_ptr members to restore binary compatibility with libpng-1.0.5
    (breaks compatibility with libpng-1.0.6).

Version 1.0.6h [April 24, 2000]
  Changed shared library so-number pattern from 2.x.y.z to xy.z (this builds
    libpng.so.10 & libpng.so.10.6h instead of libpng.so.2 & libpng.so.2.1.0.6h)
    This is a temporary change for test purposes.

Version 1.0.6i [May 2, 2000]
  Rearranged some members at the end of png_info and png_struct, to put
    unknown_chunks_num and free_me within the original size of the png_structs
    and free_me, png_read_user_fn, and png_free_fn within the original png_info,
    because some old applications allocate the structs directly instead of
    using png_create_*().
  Added documentation of user memory functions in libpng.txt/libpng.3
  Modified png_read_png so that it will use user_allocated row_pointers
    if present, unless free_me directs that it be freed, and added description
    of the use of png_set_rows() and png_get_rows() in libpng.txt/libpng.3.
  Added PNG_LEGACY_SUPPORTED macro, and #ifdef out all new (since version
    1.00) members of png_struct and png_info, to regain binary compatibility
    when you define this macro.  Capabilities lost in this event
    are user transforms (new in version 1.0.0),the user transform pointer
    (new in version 1.0.2), rgb_to_gray (new in 1.0.5), iCCP, sCAL, sPLT,
    the high-level interface, and unknown chunks support (all new in 1.0.6).
    This was necessary because of old applications that allocate the structs
    directly as authors were instructed to do in libpng-0.88 and earlier,
    instead of using png_create_*().
  Added modes PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT which
    can be used to detect codes that directly allocate the structs, and
    code to check these modes in png_read_init() and png_write_init() and
    generate a libpng error if the modes aren't set and PNG_LEGACY_SUPPORTED
    was not defined.
  Added makefile.intel and updated makefile.watcom (Pawel Mrochen)

Version 1.0.6j [May 3, 2000]
  Overloaded png_read_init() and png_write_init() with macros that convert
    calls to png_read_init_2() or png_write_init_2() that check the version
    and structure sizes.

Version 1.0.7beta11 [May 7, 2000]
  Removed the new PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT modes
    which are no longer used.
  Eliminated the three new members of png_text when PNG_LEGACY_SUPPORTED is
    defined or when neither PNG_READ_iTXt_SUPPORTED nor PNG_WRITE_iTXT_SUPPORTED
    is defined.
  Made PNG_NO_READ|WRITE_iTXt the default setting, to avoid memory
    overrun when old applications fill the info_ptr->text structure directly.
  Added PNGAPI macro, and added it to the definitions of all exported functions.
  Relocated version macro definitions ahead of the includes of zlib.h and
    pngconf.h in png.h.

Version 1.0.7beta12 [May 12, 2000]
  Revised pngset.c to avoid a problem with expanding the png_debug macro.
  Deleted some extraneous defines from pngconf.h
  Made PNG_NO_CONSOLE_IO the default condition when PNG_BUILD_DLL is defined.
  Use MSC _RPTn debugging instead of fprintf if _MSC_VER is defined.
  Added png_access_version_number() function.
  Check for mask&PNG_FREE_CHNK (for TEXT, SCAL, PCAL) in png_free_data().
  Expanded libpng.3/libpng.txt information about png_data_freer().

Version 1.0.7beta14 [May 17, 2000] (beta13 was not published)
  Changed pnggccrd.c and pngvcrd.c to handle bad adaptive filter types as
    warnings instead of errors, as pngrutil.c does.
  Set the PNG_INFO_IDAT valid flag in png_set_rows() so png_write_png()
    will actually write IDATs.
  Made the default PNG_USE_LOCAL_ARRAYS depend on PNG_DLL instead of WIN32.
  Make png_free_data() ignore its final parameter except when freeing data
    that can have multiple instances (text, sPLT, unknowns).
  Fixed a new bug in png_set_rows().
  Removed info_ptr->valid tests from png_free_data(), as in version 1.0.5.
  Added png_set_invalid() function.
  Fixed incorrect illustrations of png_destroy_write_struct() in example.c.

Version 1.0.7beta15 [May 30, 2000]
  Revised the deliberately erroneous Linux setjmp code in pngconf.h to produce
    fewer error messages.
  Rearranged checks for Z_OK to check the most likely path first in pngpread.c
    and pngwutil.c.
  Added checks in pngtest.c for png_create_*() returning NULL, and mentioned
    in libpng.txt/libpng.3 the need for applications to check this.
  Changed names of png_default_*() functions in pngtest to pngtest_*().
  Changed return type of png_get_x|y_offset_*() from png_uint_32 to png_int_32.
  Fixed some bugs in the unused PNG_INCH_CONVERSIONS functions in pngget.c
  Set each pointer to NULL after freeing it in png_free_data().
  Worked around a problem in pngconf.h; AIX's strings.h defines an "index"
    macro that conflicts with libpng's png_color_16.index. (Dimitri
    Papadapoulos)
  Added "msvc" directory with MSVC++ project files (Simon-Pierre Cadieux).

Version 1.0.7beta16 [June 4, 2000]
  Revised the workaround of AIX string.h "index" bug.
  Added a check for overlength PLTE chunk in pngrutil.c.
  Added PNG_NO_POINTER_INDEXING macro to use array-indexing instead of pointer
    indexing in pngrutil.c and pngwutil.c to accommodate a buggy compiler.
  Added a warning in png_decompress_chunk() when it runs out of data, e.g.
    when it tries to read an erroneous PhotoShop iCCP chunk.
  Added PNG_USE_DLL macro.
  Revised the copyright/disclaimer/license notice.
  Added contrib/msvctest directory

Version 1.0.7rc1 [June 9, 2000]
  Corrected the definition of PNG_TRANSFORM_INVERT_ALPHA  (0x0400 not 0x0200)
  Added contrib/visupng directory (Willem van Schaik)

Version 1.0.7beta18 [June 23, 2000]
  Revised PNGAPI definition, and pngvcrd.c to work with __GCC__
    and do not redefine PNGAPI if it is passed in via a compiler directive.
  Revised visupng/PngFile.c to remove returns from within the Try block.
  Removed leading underscores from "_PNG_H" and "_PNG_SAVE_BSD_SOURCE" macros.
  Updated contrib/visupng/cexcept.h to version 1.0.0.
  Fixed bugs in pngwrite.c and pngwutil.c that prevented writing iCCP chunks.

Version 1.0.7rc2 [June 28, 2000]
  Updated license to include disclaimers required by UCITA.
  Fixed "DJBPP" typo in pnggccrd.c introduced in beta18.

Version 1.0.7 [July 1, 2000]
  Revised the definition of "trans_values" in libpng.3/libpng.txt

Version 1.0.8beta1 [July 8, 2000]
  Added png_free(png_ptr, key) two places in pngpread.c to stop memory leaks.
  Changed PNG_NO_STDIO to PNG_NO_CONSOLE_IO, several places in pngrutil.c and
     pngwutil.c.
  Changed PNG_EXPORT_VAR to use PNG_IMPEXP, in pngconf.h.
  Removed unused "#include <assert.h>" from png.c
  Added WindowsCE support.
  Revised pnggccrd.c to work with gcc-2.95.2 and in the Cygwin environment.

Version 1.0.8beta2 [July 10, 2000]
  Added project files to the wince directory and made further revisions
     of pngtest.c, pngrio.c, and pngwio.c in support of WindowsCE.

Version 1.0.8beta3 [July 11, 2000]
  Only set the PNG_FLAG_FREE_TRNS or PNG_FREE_TRNS flag in png_handle_tRNS()
     for indexed-color input files to avoid potential double-freeing trans array
     under some unusual conditions; problem was introduced in version 1.0.6f.
  Further revisions to pngtest.c and files in the wince subdirectory.

Version 1.0.8beta4 [July 14, 2000]
  Added the files pngbar.png and pngbar.jpg to the distribution.
  Added makefile.cygwin, and cygwin support in pngconf.h
  Added PNG_NO_ZALLOC_ZERO macro (makes png_zalloc skip zeroing memory)

Version 1.0.8rc1 [July 16, 2000]
  Revised png_debug() macros and statements to eliminate compiler warnings.

Version 1.0.8 [July 24, 2000]
  Added png_flush() in pngwrite.c, after png_write_IEND().
  Updated makefile.hpux to build a shared library.

Version 1.0.9beta1 [November 10, 2000]
  Fixed typo in scripts/makefile.hpux
  Updated makevms.com in scripts and contrib/* and contrib/* (Martin Zinser)
  Fixed seqence-point bug in contrib/pngminus/png2pnm (Martin Zinser)
  Changed "cdrom.com" in documentation to "libpng.org"
  Revised pnggccrd.c to get it all working, and updated makefile.gcmmx (Greg).
  Changed type of "params" from voidp to png_voidp in png_read|write_png().
  Make sure PNGAPI and PNG_IMPEXP are defined in pngconf.h.
  Revised the 3 instances of WRITEFILE in pngtest.c.
  Relocated "msvc" and "wince" project subdirectories into "dll" subdirectory.
  Updated png.rc in dll/msvc project
  Revised makefile.dec to define and use LIBPATH and INCPATH
  Increased size of global png_libpng_ver[] array from 12 to 18 chars.
  Made global png_libpng_ver[], png_sig[] and png_pass_*[] arrays const.
  Removed duplicate png_crc_finish() from png_handle_bKGD() function.
  Added a warning when application calls png_read_update_info() multiple times.
  Revised makefile.cygwin
  Fixed bugs in iCCP support in pngrutil.c and pngwutil.c.
  Replaced png_set_empty_plte_permitted() with png_permit_mng_features().

Version 1.0.9beta2 [November 19, 2000]
  Renamed the "dll" subdirectory "projects".
  Added borland project files to "projects" subdirectory.
  Set VS_FF_PRERELEASE and VS_FF_PATCHED flags in msvc/png.rc when appropriate.
  Add error message in png_set_compression_buffer_size() when malloc fails.

Version 1.0.9beta3 [November 23, 2000]
  Revised PNG_LIBPNG_BUILD_TYPE macro in png.h, used in the msvc project.
  Removed the png_flush() in pngwrite.c that crashes some applications
    that don't set png_output_flush_fn.
  Added makefile.macosx and makefile.aix to scripts directory.

Version 1.0.9beta4 [December 1, 2000]
  Change png_chunk_warning to png_warning in png_check_keyword().
  Increased the first part of msg buffer from 16 to 18 in png_chunk_error().

Version 1.0.9beta5 [December 15, 2000]
  Added support for filter method 64 (for PNG datastreams embedded in MNG).

Version 1.0.9beta6 [December 18, 2000]
  Revised png_set_filter() to accept filter method 64 when appropriate.
  Added new PNG_HAVE_PNG_SIGNATURE bit to png_ptr->mode and use it to
    help prevent applications from using MNG features in PNG datastreams.
  Added png_permit_mng_features() function.
  Revised libpng.3/libpng.txt.  Changed "filter type" to "filter method".

Version 1.0.9rc1 [December 23, 2000]
  Revised test for PNG_HAVE_PNG_SIGNATURE in pngrutil.c
  Fixed error handling of unknown compression type in png_decompress_chunk().
  In pngconf.h, define __cdecl when _MSC_VER is defined.

Version 1.0.9beta7 [December 28, 2000]
  Changed PNG_TEXT_COMPRESSION_zTXt to PNG_COMPRESSION_TYPE_BASE several places.
  Revised memory management in png_set_hIST and png_handle_hIST in a backward
    compatible manner.  PLTE and tRNS were revised similarly.
  Revised the iCCP chunk reader to ignore trailing garbage.

Version 1.0.9beta8 [January 12, 2001]
  Moved pngasmrd.h into pngconf.h.
  Improved handling of out-of-spec garbage iCCP chunks generated by PhotoShop.

Version 1.0.9beta9 [January 15, 2001]
  Added png_set_invalid, png_permit_mng_features, and png_mmx_supported to
    wince and msvc project module definition files.
  Minor revision of makefile.cygwin.
  Fixed bug with progressive reading of narrow interlaced images in pngpread.c

Version 1.0.9beta10 [January 16, 2001]
  Do not typedef png_FILE_p in pngconf.h when PNG_NO_STDIO is defined.
  Fixed "png_mmx_supported" typo in project definition files.

Version 1.0.9beta11 [January 19, 2001]
  Updated makefile.sgi to make shared library.
  Removed png_mmx_support() function and disabled PNG_MNG_FEATURES_SUPPORTED
    by default, for the benefit of DLL forward compatibility.  These will
    be re-enabled in version 1.2.0.

Version 1.0.9rc2 [January 22, 2001]
  Revised cygwin support.

Version 1.0.9 [January 31, 2001]
  Added check of cygwin's ALL_STATIC in pngconf.h
  Added "-nommx" parameter to contrib/gregbook/rpng2-win and rpng2-x demos.

Version 1.0.10beta1 [March 14, 2001]
  Revised makefile.dec, makefile.sgi, and makefile.sggcc; added makefile.hpgcc.
  Reformatted libpng.3 to eliminate bad line breaks.
  Added checks for _mmx_supported in the read_filter_row function of pnggccrd.c
  Added prototype for png_mmx_support() near the top of pnggccrd.c
  Moved some error checking from png_handle_IHDR to png_set_IHDR.
  Added PNG_NO_READ_SUPPORTED and PNG_NO_WRITE_SUPPORTED macros.
  Revised png_mmx_support() function in pnggccrd.c
  Restored version 1.0.8 PNG_WRITE_EMPTY_PLTE_SUPPORTED behavior in pngwutil.c
  Fixed memory leak in contrib/visupng/PngFile.c
  Fixed bugs in png_combine_row() in pnggccrd.c and pngvcrd.c (C version)
  Added warnings when retrieving or setting gamma=0.
  Increased the first part of msg buffer from 16 to 18 in png_chunk_warning().

Version 1.0.10rc1 [March 23, 2001]
  Changed all instances of memcpy, strcpy, and strlen to png_memcpy, png_strcpy,
    and png_strlen.
  Revised png_mmx_supported() function in pnggccrd.c to return proper value.
  Fixed bug in progressive reading (pngpread.c) with small images (height < 8).

Version 1.0.10 [March 30, 2001]
  Deleted extraneous space (introduced in 1.0.9) from line 42 of makefile.cygwin
  Added beos project files (Chris Herborth)

Version 1.0.11beta1 [April 3, 2001]
  Added type casts on several png_malloc() calls (Dimitri Papadapoulos).
  Removed a no-longer needed AIX work-around from pngconf.h
  Changed several "//" single-line comments to C-style in pnggccrd.c

Version 1.0.11beta2 [April 11, 2001]
  Removed PNGAPI from several functions whose prototypes did not have PNGAPI.
  Updated scripts/pngos2.def

Version 1.0.11beta3 [April 14, 2001]
  Added checking the results of many instances of png_malloc() for NULL

Version 1.0.11beta4 [April 20, 2001]
  Undid the changes from version 1.0.11beta3.  Added a check for NULL return
    from user's malloc_fn().
  Removed some useless type casts of the NULL pointer.
  Added makefile.netbsd

Version 1.0.11 [April 27, 2001]
  Revised makefile.netbsd

Version 1.0.12beta1 [May 14, 2001]
  Test for Windows platform in pngconf.h when including malloc.h (Emmanuel Blot)
  Updated makefile.cygwin and handling of Cygwin's ALL_STATIC in pngconf.h
  Added some never-to-be-executed code in pnggccrd.c to quiet compiler warnings.
  Eliminated the png_error about apps using png_read|write_init().  Instead,
    libpng will reallocate the png_struct and info_struct if they are too small.
    This retains future binary compatibility for old applications written for
    libpng-0.88 and earlier.

Version 1.2.0beta1 [May 6, 2001]
  Bumped DLLNUM to 2.
  Re-enabled PNG_MNG_FEATURES_SUPPORTED and enabled PNG_ASSEMBLER_CODE_SUPPORTED
    by default.
  Added runtime selection of MMX features.
  Added png_set_strip_error_numbers function and related macros.

Version 1.2.0beta2 [May 7, 2001]
  Finished merging 1.2.0beta1 with version 1.0.11
  Added a check for attempts to read or write PLTE in grayscale PNG datastreams.

Version 1.2.0beta3 [May 17, 2001]
  Enabled user memory function by default.
  Modified png_create_struct so it passes user mem_ptr to user memory allocator.
  Increased png_mng_features flag from png_byte to png_uint_32.
  Bumped shared-library (so-number) and dll-number to 3.

Version 1.2.0beta4 [June 23, 2001]
  Check for missing profile length field in iCCP chunk and free chunk_data
     in case of truncated iCCP chunk.
  Bumped shared-library number to 3 in makefile.sgi and makefile.sggcc
  Bumped dll-number from 2 to 3 in makefile.cygwin
  Revised contrib/gregbook/rpng*-x.c to avoid a memory leak and to exit cleanly
     if user attempts to run it on an 8-bit display.
  Updated contrib/gregbook
  Use png_malloc instead of png_zalloc to allocate palette in pngset.c
  Updated makefile.ibmc
  Added some typecasts to eliminate gcc 3.0 warnings.  Changed prototypes
     of png_write_oFFS width and height from png_uint_32 to png_int_32.
  Updated example.c
  Revised prototypes for png_debug_malloc and png_debug_free in pngtest.c

Version 1.2.0beta5 [August 8, 2001]
  Revised contrib/gregbook
  Revised makefile.gcmmx
  Revised pnggccrd.c to conditionally compile some thread-unsafe code only
     when PNG_THREAD_UNSAFE_OK is defined.
  Added tests to prevent pngwutil.c from writing a bKGD or tRNS chunk with
     value exceeding 2^bit_depth-1
  Revised makefile.sgi and makefile.sggcc
  Replaced calls to fprintf(stderr,...) with png_warning() in pnggccrd.c
  Removed restriction that do_invert_mono only operate on 1-bit opaque files

Version 1.2.0 [September 1, 2001]
  Changed a png_warning() to png_debug() in pnggccrd.c
  Fixed contrib/gregbook/rpng-x.c, rpng2-x.c to avoid crash with XFreeGC().

Version 1.2.1beta1 [October 19, 2001]
  Revised makefile.std in contrib/pngminus
  Include background_1 in png_struct regardless of gamma support.
  Revised makefile.netbsd and makefile.macosx, added makefile.darwin.
  Revised example.c to provide more details about using row_callback().

Version 1.2.1beta2 [October 25, 2001]
  Added type cast to each NULL appearing in a function call, except for
    WINCE functions.
  Added makefile.so9.

Version 1.2.1beta3 [October 27, 2001]
  Removed type casts from all NULLs.
  Simplified png_create_struct_2().

Version 1.2.1beta4 [November 7, 2001]
  Revised png_create_info_struct() and png_creat_struct_2().
  Added error message if png_write_info() was omitted.
  Type cast NULLs appearing in function calls when _NO_PROTO or
    PNG_TYPECAST_NULL is defined.

Version 1.2.1rc1 [November 24, 2001]
  Type cast NULLs appearing in function calls except when PNG_NO_TYPECAST_NULL
    is defined.
  Changed typecast of "size" argument to png_size_t in pngmem.c calls to
    the user malloc_fn, to agree with the prototype in png.h
  Added a pop/push operation to pnggccrd.c, to preserve Eflag (Maxim Sobolev)
  Updated makefile.sgi to recognize LIBPATH and INCPATH.
  Updated various makefiles so "make clean" does not remove previous major
    version of the shared library.

Version 1.2.1rc2 [December 4, 2001]
  Always allocate 256-entry internal palette, hist, and trans arrays, to
    avoid out-of-bounds memory reference caused by invalid PNG datastreams.
  Added a check for prefix_length > data_length in iCCP chunk handler.

Version 1.2.1 [December 7, 2001]
  None.

Version 1.2.2beta1 [February 22, 2002]
  Fixed a bug with reading the length of iCCP profiles (Larry Reeves).
  Revised makefile.linux, makefile.gcmmx, and makefile.sgi to generate
    libpng.a, libpng12.so (not libpng.so.3), and libpng12/png.h
  Revised makefile.darwin to remove "-undefined suppress" option.
  Added checks for gamma and chromaticity values over 21474.83, which exceed
    the limit for PNG unsigned 32-bit integers when encoded.
  Revised calls to png_create_read_struct() and png_create_write_struct()
    for simpler debugging.
  Revised png_zalloc() so zlib handles errors (uses PNG_FLAG_MALLOC_NULL_MEM_OK)

Version 1.2.2beta2 [February 23, 2002]
  Check chunk_length and idat_size for invalid (over PNG_MAX_UINT) lengths.
  Check for invalid image dimensions in png_get_IHDR.
  Added missing "fi;" in the install target of the SGI makefiles.
  Added install-static to all makefiles that make shared libraries.
  Always do gamma compensation when image is partially transparent.

Version 1.2.2beta3 [March 7, 2002]
  Compute background.gray and background_1.gray even when color_type is RGB
    in case image gets reduced to gray later.
  Modified shared-library makefiles to install pkgconfig/libpngNN.pc.
  Export (with PNGAPI) png_zalloc, png_zfree, and png_handle_as_unknown
  Removed unused png_write_destroy_info prototype from png.h
  Eliminated incorrect use of width_mmx from pnggccrd.c in pixel_bytes == 8 case
  Added install-shared target to all makefiles that make shared libraries.
  Stopped a double free of palette, hist, and trans when not using free_me.
  Added makefile.32sunu for Sun Ultra 32 and makefile.64sunu for Sun Ultra 64.

Version 1.2.2beta4 [March 8, 2002]
  Compute background.gray and background_1.gray even when color_type is RGB
    in case image gets reduced to gray later (Jason Summers).
  Relocated a misplaced /bin/rm in the "install-shared" makefile targets
  Added PNG_1_0_X macro which can be used to build a 1.0.x-compatible library.

Version 1.2.2beta5 [March 26, 2002]
  Added missing PNGAPI to several function definitions.
  Check for invalid bit_depth or color_type in png_get_IHDR(), and
    check for missing PLTE or IHDR in png_push_read_chunk() (Matthias Clasen).
  Revised iTXt support to accept NULL for lang and lang_key.
  Compute gamma for color components of background even when color_type is gray.
  Changed "()" to "{}" in scripts/libpng.pc.in.
  Revised makefiles to put png.h and pngconf.h only in $prefix/include/libpngNN
  Revised makefiles to make symlink to libpng.so.NN in addition to libpngNN.so

Version 1.2.2beta6 [March 31, 2002]

Version 1.0.13beta1 [March 31, 2002]
  Prevent png_zalloc() from trying to memset memory that it failed to acquire.
  Add typecasts of PNG_MAX_UINT in pngset_cHRM_fixed() (Matt Holgate).
  Ensure that the right function (user or default) is used to free the
    png_struct after an error in png_create_read_struct_2().

Version 1.2.2rc1 [April 7, 2002]

Version 1.0.13rc1 [April 7, 2002]
  Save the ebx register in pnggccrd.c (Sami Farin)
  Add "mem_ptr = png_ptr->mem_ptr" in png_destroy_write_struct() (Paul Gardner).
  Updated makefiles to put headers in include/libpng and remove old include/*.h.

Version 1.2.2 [April 15, 2002]

Version 1.0.13 [April 15, 2002]
  Revised description of png_set_filter() in libpng.3/libpng.txt.
  Revised makefile.netbsd and added makefile.neNNbsd and makefile.freebsd

Version 1.0.13patch01 [April 17, 2002]

Version 1.2.2patch01 [April 17, 2002]
  Changed ${PNGMAJ}.${PNGVER} bug to ${PNGVER} in makefile.sgi and
    makefile.sggcc
  Fixed VER -> PNGVER typo in makefile.macosx and added install-static to
    install
  Added install: target to makefile.32sunu and makefile.64sunu

Version 1.0.13patch03 [April 18, 2002]

Version 1.2.2patch03 [April 18, 2002]
  Revised 15 makefiles to link libpng.a to libpngNN.a and the include libpng
  subdirectory to libpngNN subdirectory without the full pathname.
  Moved generation of libpng.pc from "install" to "all" in 15 makefiles.

Version 1.2.3rc1 [April 28, 2002]
  Added install-man target to 15 makefiles (Dimitri Papadopolous-Orfanos).
  Added $(DESTDIR) feature to 24 makefiles (Tim Mooney)
  Fixed bug with $prefix, should be $(prefix) in makefile.hpux.
  Updated cygwin-specific portion of pngconf.h and revised makefile.cygwin
  Added a link from libpngNN.pc to libpng.pc in 15 makefiles.
  Added links from include/libpngNN/*.h to include/*.h in 24 makefiles.
  Revised makefile.darwin to make relative links without full pathname.
  Added setjmp() at the end of png_create_*_struct_2() in case user forgets
    to put one in their application.
  Restored png_zalloc() and png_zfree() prototypes to version 1.2.1 and
    removed them from module definition files.

Version 1.2.3rc2 [May 1, 2002]
  Fixed bug in reporting number of channels in pngget.c and pngset.c,
    that was introduced in version 1.2.2beta5.
  Exported png_zalloc(), png_zfree(), png_default_read(), png_default_write(),
    png_default_flush(), and png_push_fill_buffer() and included them in
    module definition files.
  Added "libpng.pc" dependency to the "install-shared" target in 15 makefiles.

Version 1.2.3rc3 [May 1, 2002]
  Revised prototype for png_default_flush()
  Remove old libpng.pc and libpngNN.pc before installing new ones.

Version 1.2.3rc4 [May 2, 2002]
  Typos in *.def files (png_default_read|write -> png_default_read|write_data)
  In makefiles, changed rm libpng.NN.pc to rm libpngNN.pc
  Added libpng-config and libpngNN-config and modified makefiles to install
    them.
  Changed $(MANPATH) to $(DESTDIR)$(MANPATH) in makefiles
  Added "Win32 DLL VB" configuration to projects/msvc/libpng.dsp

Version 1.2.3rc5 [May 11, 2002]
  Changed "error" and "message" in prototypes to "error_message" and
    "warning_message" to avoid namespace conflict.
  Revised 15 makefiles to build libpng-config from libpng-config-*.in
  Once more restored png_zalloc and png_zfree to regular nonexported form.
  Restored png_default_read|write_data, png_default_flush, png_read_fill_buffer
    to nonexported form, but with PNGAPI, and removed them from module def
    files.

Version 1.2.3rc6 [May 14, 2002]
  Removed "PNGAPI" from png_zalloc() and png_zfree() in png.c
  Changed "Gz" to "Gd" in projects/msvc/libpng.dsp and zlib.dsp.
  Removed leftover libpng-config "sed" script from four makefiles.
  Revised libpng-config creating script in 16 makefiles.

Version 1.2.3 [May 22, 2002]
  Revised libpng-config target in makefile.cygwin.
  Removed description of png_set_mem_fn() from documentation.
  Revised makefile.freebsd.
  Minor cosmetic changes to 15 makefiles, e.g., $(DI) = $(DESTDIR)/$(INCDIR).
  Revised projects/msvc/README.txt
  Changed -lpng to -lpngNN in LDFLAGS in several makefiles.

Version 1.2.4beta1 [May 24, 2002]
  Added libpng.pc and libpng-config to "all:" target in 16 makefiles.
  Fixed bug in 16 makefiles: $(DESTDIR)/$(LIBPATH) to $(DESTDIR)$(LIBPATH)
  Added missing "\" before closing double quote in makefile.gcmmx.
  Plugged various memory leaks; added png_malloc_warn() and png_set_text_2()
    functions.

Version 1.2.4beta2 [June 25, 2002]
  Plugged memory leak of png_ptr->current_text (Matt Holgate).
  Check for buffer overflow before reading CRC in pngpread.c (Warwick Allison)
  Added -soname to the loader flags in makefile.dec, makefile.sgi, and
    makefile.sggcc.
  Added "test-installed" target to makefile.linux, makefile.gcmmx,
    makefile.sgi, and makefile.sggcc.

Version 1.2.4beta3 [June 28, 2002]
  Plugged memory leak of row_buf in pngtest.c when there is a png_error().
  Detect buffer overflow in pngpread.c when IDAT is corrupted with extra data.
  Added "test-installed" target to makefile.32sunu, makefile.64sunu,
    makefile.beos, makefile.darwin, makefile.dec, makefile.macosx,
    makefile.solaris, makefile.hpux, makefile.hpgcc, and makefile.so9.

Version 1.2.4rc1 and 1.0.14rc1 [July 2, 2002]
  Added "test-installed" target to makefile.cygwin and makefile.sco.
  Revised pnggccrd.c to be able to back out version 1.0.x via PNG_1_0_X macro.

Version 1.2.4 and 1.0.14 [July 8, 2002]
  Changed png_warning() to png_error() when width is too large to process.

Version 1.2.4patch01 [July 20, 2002]
  Revised makefile.cygwin to use DLL number 12 instead of 13.

Version 1.2.5beta1 [August 6, 2002]
  Added code to contrib/gregbook/readpng2.c to ignore unused chunks.
  Replaced toucan.png in contrib/gregbook (it has been corrupt since 1.0.11)
  Removed some stray *.o files from contrib/gregbook.
  Changed png_error() to png_warning() about "Too much data" in pngpread.c
    and about "Extra compressed data" in pngrutil.c.
  Prevent png_ptr->pass from exceeding 7 in png_push_finish_row().
  Updated makefile.hpgcc
  Updated png.c and pnggccrd.c handling of return from png_mmx_support()

Version 1.2.5beta2 [August 15, 2002]
  Only issue png_warning() about "Too much data" in pngpread.c when avail_in
    is nonzero.
  Updated makefiles to install a separate libpng.so.3 with its own rpath.

Version 1.2.5rc1 and 1.0.15rc1 [August 24, 2002]
  Revised makefiles to not remove previous minor versions of shared libraries.

Version 1.2.5rc2 and 1.0.15rc2 [September 16, 2002]
  Revised 13 makefiles to remove "-lz" and "-L$(ZLIBLIB)", etc., from shared
    library loader directive.
  Added missing "$OBJSDLL" line to makefile.gcmmx.
  Added missing "; fi" to makefile.32sunu.

Version 1.2.5rc3 and 1.0.15rc3 [September 18, 2002]
  Revised libpng-config script.

Version 1.2.5 and 1.0.15 [October 3, 2002]
  Revised makefile.macosx, makefile.darwin, makefile.hpgcc, and makefile.hpux,
    and makefile.aix.
  Relocated two misplaced PNGAPI lines in pngtest.c

Version 1.2.6beta1 [October 22, 2002]
  Commented out warning about uninitialized mmx_support in pnggccrd.c.
  Changed "IBMCPP__" flag to "__IBMCPP__" in pngconf.h.
  Relocated two more misplaced PNGAPI lines in pngtest.c
  Fixed memory overrun bug in png_do_read_filler() with 16-bit datastreams,
    introduced in version 1.0.2.
  Revised makefile.macosx, makefile.dec, makefile.aix, and makefile.32sunu.

Version 1.2.6beta2 [November 1, 2002]
  Added libpng-config "--ldopts" output.
  Added "AR=ar" and "ARFLAGS=rc" and changed "ar rc" to "$(AR) $(ARFLAGS)"
    in makefiles.

Version 1.2.6beta3 [July 18, 2004]
  Reverted makefile changes from version 1.2.6beta2 and some of the changes
    from version 1.2.6beta1; these will be postponed until version 1.2.7.
    Version 1.2.6 is going to be a simple bugfix release.
  Changed the one instance of "ln -sf" to "ln -f -s" in each Sun makefile.
  Fixed potential overrun in pngerror.c by using strncpy instead of memcpy.
  Added "#!/bin/sh" at the top of configure, for recognition of the
    'x' flag under Cygwin (Cosmin).
  Optimized vacuous tests that silence compiler warnings, in png.c (Cosmin).
  Added support for PNG_USER_CONFIG, in pngconf.h (Cosmin).
  Fixed the special memory handler for Borland C under DOS, in pngmem.c
    (Cosmin).
  Removed some spurious assignments in pngrutil.c (Cosmin).
  Replaced 65536 with 65536L, and 0xffff with 0xffffL, to silence warnings
    on 16-bit platforms (Cosmin).
  Enclosed shift op expressions in parentheses, to silence warnings (Cosmin).
  Used proper type png_fixed_point, to avoid problems on 16-bit platforms,
    in png_handle_sRGB() (Cosmin).
  Added compression_type to png_struct, and optimized the window size
    inside the deflate stream (Cosmin).
  Fixed definition of isnonalpha(), in pngerror.c and pngrutil.c (Cosmin).
  Fixed handling of unknown chunks that come after IDAT (Cosmin).
  Allowed png_error() and png_warning() to work even if png_ptr == NULL
    (Cosmin).
  Replaced row_info->rowbytes with row_bytes in png_write_find_filter()
    (Cosmin).
  Fixed definition of PNG_LIBPNG_VER_DLLNUM (Simon-Pierre).
  Used PNG_LIBPNG_VER and PNG_LIBPNG_VER_STRING instead of the hardcoded
    values in png.c (Simon-Pierre, Cosmin).
  Initialized png_libpng_ver[] with PNG_LIBPNG_VER_STRING (Simon-Pierre).
  Replaced PNG_LIBPNG_VER_MAJOR with PNG_LIBPNG_VER_DLLNUM in png.rc
    (Simon-Pierre).
  Moved the definition of PNG_HEADER_VERSION_STRING near the definitions
    of the other PNG_LIBPNG_VER_... symbols in png.h (Cosmin).
  Relocated #ifndef PNGAPI guards in pngconf.h (Simon-Pierre, Cosmin).
  Updated scripts/makefile.vc(a)win32 (Cosmin).
  Updated the MSVC project (Simon-Pierre, Cosmin).
  Updated the Borland C++ Builder project (Cosmin).
  Avoided access to asm_flags in pngvcrd.c, if PNG_1_0_X is defined (Cosmin).
  Commented out warning about uninitialized mmx_support in pngvcrd.c (Cosmin).
  Removed scripts/makefile.bd32 and scripts/pngdef.pas (Cosmin).
  Added extra guard around inclusion of Turbo C memory headers, in pngconf.h
    (Cosmin).
  Renamed projects/msvc/ to projects/visualc6/, and projects/borland/ to
    projects/cbuilder5/ (Cosmin).
  Moved projects/visualc6/png32ms.def to scripts/pngw32.def,
    and projects/visualc6/png.rc to scripts/pngw32.rc (Cosmin).
  Added projects/visualc6/pngtest.dsp; removed contrib/msvctest/ (Cosmin).
  Changed line endings to DOS style in cbuilder5 and visualc6 files, even
    in the tar.* distributions (Cosmin).
  Updated contrib/visupng/VisualPng.dsp (Cosmin).
  Updated contrib/visupng/cexcept.h to version 2.0.0 (Cosmin).
  Added a separate distribution with "configure" and supporting files (Junichi).

Version 1.2.6beta4 [July 28, 2004]
  Added user ability to change png_size_t via a PNG_SIZE_T macro.
  Added png_sizeof() and png_convert_size() functions.
  Added PNG_SIZE_MAX (maximum value of a png_size_t variable.
  Added check in png_malloc_default() for (size_t)size != (png_uint_32)size
    which would indicate an overflow.
  Changed sPLT failure action from png_error to png_warning and abandon chunk.
  Changed sCAL and iCCP failures from png_error to png_warning and abandon.
  Added png_get_uint_31(png_ptr, buf) function.
  Added PNG_UINT_32_MAX macro.
  Renamed PNG_MAX_UINT to PNG_UINT_31_MAX.
  Made png_zalloc() issue a png_warning and return NULL on potential
    overflow.
  Turn on PNG_NO_ZALLOC_ZERO by default in version 1.2.x
  Revised "clobber list" in pnggccrd.c so it will compile under gcc-3.4.
  Revised Borland portion of png_malloc() to return NULL or issue
    png_error() according to setting of PNG_FLAG_MALLOC_NULL_MEM_OK.
  Added PNG_NO_SEQUENTIAL_READ_SUPPORTED macro to conditionally remove
    sequential read support.
  Added some "#if PNG_WRITE_SUPPORTED" blocks.
  Added #ifdef to remove some redundancy in png_malloc_default().
  Use png_malloc instead of png_zalloc to allocate the pallete.

Version 1.0.16rc1 and 1.2.6rc1 [August 4, 2004]
  Fixed buffer overflow vulnerability in png_handle_tRNS()
  Fixed integer arithmetic overflow vulnerability in png_read_png().
  Fixed some harmless bugs in png_handle_sBIT, etc, that would cause
    duplicate chunk types to go undetected.
  Fixed some timestamps in the -config version
  Rearranged order of processing of color types in png_handle_tRNS().
  Added ROWBYTES macro to calculate rowbytes without integer overflow.
  Updated makefile.darwin and removed makefile.macosx from scripts directory.
  Imposed default one million column, one-million row limits on the image
    dimensions, and added png_set_user_limits() function to override them.
  Revised use of PNG_SET_USER_LIMITS_SUPPORTED macro.
  Fixed wrong cast of returns from png_get_user_width|height_max().
  Changed some "keep the compiler happy" from empty statements to returns,
  Revised libpng.txt to remove 1.2.x stuff from the 1.0.x distribution

Version 1.0.16rc2 and 1.2.6rc2 [August 7, 2004]
  Revised makefile.darwin and makefile.solaris.  Removed makefile.macosx.
  Revised pngtest's png_debug_malloc() to use png_malloc() instead of
    png_malloc_default() which is not supposed to be exported.
  Fixed off-by-one error in one of the conversions to PNG_ROWBYTES() in
    pngpread.c.  Bug was introduced in 1.2.6rc1.
  Fixed bug in RGB to RGBX transformation introduced in 1.2.6rc1.
  Fixed old bug in RGB to Gray transformation.
  Fixed problem with 64-bit compilers by casting arguments to abs()
    to png_int_32.
  Changed "ln -sf" to "ln -f -s" in three makefiles (solaris, sco, so9).
  Changed "HANDLE_CHUNK_*" to "PNG_HANDLE_CHUNK_*" (Cosmin)
  Added "-@/bin/rm -f $(DL)/$(LIBNAME).so.$(PNGMAJ)" to 15 *NIX makefiles.
  Added code to update the row_info->colortype in png_do_read_filler() (MSB).

Version 1.0.16rc3 and 1.2.6rc3 [August 9, 2004]
  Eliminated use of "abs()" in testing cHRM and gAMA values, to avoid
    trouble with some 64-bit compilers.  Created PNG_OUT_OF_RANGE() macro.
  Revised documentation of png_set_keep_unknown_chunks().
  Check handle_as_unknown status in pngpread.c, as in pngread.c previously.
  Moved  "PNG_HANDLE_CHUNK_*" macros out of PNG_INTERNAL section of png.h
  Added "rim" definitions for CONST4 and CONST6 in pnggccrd.c

Version 1.0.16rc4 and 1.2.6rc4 [August 10, 2004]
  Fixed mistake in pngtest.c introduced in 1.2.6rc2 (declaration of
    "pinfo" was out of place).

Version 1.0.16rc5 and 1.2.6rc5 [August 10, 2004]
  Moved  "PNG_HANDLE_CHUNK_*" macros out of PNG_ASSEMBLER_CODE_SUPPORTED
     section of png.h where they were inadvertently placed in version rc3.

Version 1.2.6 and 1.0.16 [August 15, 2004]
  Revised pngtest so memory allocation testing is only done when PNG_DEBUG==1.

Version 1.2.7beta1 [August 26, 2004]
  Removed unused pngasmrd.h file.
  Removed references to uu.net for archived files.  Added references to
    PNG Spec (second edition) and the PNG ISO/IEC Standard.
  Added "test-dd" target in 15 makefiles, to run pngtest in DESTDIR.
  Fixed bug with "optimized window size" in the IDAT datastream, that
    causes libpng to write PNG files with incorrect zlib header bytes.

Version 1.2.7beta2 [August 28, 2004]
  Fixed bug with sCAL chunk and big-endian machines (David Munro).
  Undid new code added in 1.2.6rc2 to update the color_type in
    png_set_filler().
  Added png_set_add_alpha() that updates color type.

Version 1.0.17rc1 and 1.2.7rc1 [September 4, 2004]
  Revised png_set_strip_filler() to not remove alpha if color_type has alpha.

Version 1.2.7 and 1.0.17 [September 12, 2004]
  Added makefile.hp64
  Changed projects/msvc/png32ms.def to scripts/png32ms.def in makefile.cygwin

Version 1.2.8beta1 [November 1, 2004]
  Fixed bug in png_text_compress() that would fail to complete a large block.
  Fixed bug, introduced in libpng-1.2.7, that overruns a buffer during
    strip alpha operation in png_do_strip_filler().
  Added PNG_1_2_X definition in pngconf.h
  Use #ifdef to comment out png_info_init in png.c and png_read_init in
    pngread.c (as of 1.3.0)

Version 1.2.8beta2 [November 2, 2004]
  Reduce color_type to a nonalpha type after strip alpha operation in
    png_do_strip_filler().

Version 1.2.8beta3 [November 3, 2004]
  Revised definitions of PNG_MAX_UINT_32, PNG_MAX_SIZE, and PNG_MAXSUM

Version 1.2.8beta4 [November 12, 2004]
  Fixed (again) definition of PNG_LIBPNG_VER_DLLNUM in png.h (Cosmin).
  Added PNG_LIBPNG_BUILD_PRIVATE in png.h (Cosmin).
  Set png_ptr->zstream.data_type to Z_BINARY, to avoid unnecessary detection
    of data type in deflate (Cosmin).
  Deprecated but continue to support SPECIALBUILD and PRIVATEBUILD in favor of
    PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING.

Version 1.2.8beta5 [November 20, 2004]
  Use png_ptr->flags instead of png_ptr->transformations to pass
    PNG_STRIP_ALPHA info to png_do_strip_filler(), to preserve ABI
    compatibility.
  Revised handling of SPECIALBUILD, PRIVATEBUILD,
    PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING.

Version 1.2.8rc1 [November 24, 2004]
  Moved handling of BUILD macros from pngconf.h to png.h
  Added definition of PNG_LIBPNG_BASE_TYPE in png.h, inadvertently
    omitted from beta5.
  Revised scripts/pngw32.rc
  Despammed mailing addresses by masking "@" with "at".
  Inadvertently installed a supposedly faster test version of pngrutil.c

Version 1.2.8rc2 [November 26, 2004]
  Added two missing "\" in png.h
  Change tests in pngread.c and pngpread.c to
    if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
       png_do_read_transformations(png_ptr);

Version 1.2.8rc3 [November 28, 2004]
  Reverted pngrutil.c to version libpng-1.2.8beta5.
  Added scripts/makefile.elf with supporting code in pngconf.h for symbol
    versioning (John Bowler).

Version 1.2.8rc4 [November 29, 2004]
  Added projects/visualc7 (Simon-pierre).

Version 1.2.8rc5 [November 29, 2004]
  Fixed new typo in scripts/pngw32.rc

Version 1.2.8 [December 3, 2004]
  Removed projects/visualc7, added projects/visualc71.

Version 1.2.9beta1 [February 21, 2006]
  Initialized some structure members in pngwutil.c to avoid gcc-4.0.0 complaints
  Revised man page and libpng.txt to make it clear that one should not call
    png_read_end or png_write_end after png_read_png or png_write_png.
  Updated references to png-mng-implement mailing list.
  Fixed an incorrect typecast in pngrutil.c
  Added PNG_NO_READ_SUPPORTED conditional for making a write-only library.
  Added PNG_NO_WRITE_INTERLACING_SUPPORTED conditional.
  Optimized alpha-inversion loops in pngwtran.c
  Moved test for nonzero gamma outside of png_build_gamma_table() in pngrtran.c
  Make sure num_trans is <= 256 before copying data in png_set_tRNS().
  Make sure num_palette is <= 256 before copying data in png_set_PLTE().
  Interchanged order of write_swap_alpha and write_invert_alpha transforms.
  Added parentheses in the definition of PNG_LIBPNG_BUILD_TYPE (Cosmin).
  Optimized zlib window flag (CINFO) in contrib/pngsuite/*.png (Cosmin).
  Updated scripts/makefile.bc32 for Borland C++ 5.6 (Cosmin).
  Exported png_get_uint_32, png_save_uint_32, png_get_uint_16, png_save_uint_16,
    png_get_int_32, png_save_int_32, png_get_uint_31 (Cosmin).
  Added type cast (png_byte) in png_write_sCAL() (Cosmin).
  Fixed scripts/makefile.cygwin (Christian Biesinger, Cosmin).
  Default iTXt support was inadvertently enabled.

Version 1.2.9beta2 [February 21, 2006]
  Check for png_rgb_to_gray and png_gray_to_rgb read transformations before
    checking for png_read_dither in pngrtran.c
  Revised checking of chromaticity limits to accommodate extended RGB
    colorspace (John Denker).
  Changed line endings in some of the project files to CRLF, even in the
    "Unix" tar distributions (Cosmin).
  Made png_get_int_32 and png_save_int_32 always available (Cosmin).
  Updated scripts/pngos2.def, scripts/pngw32.def and projects/wince/png32ce.def
    with the newly exported functions.
  Eliminated distributions without the "configure" script.
  Updated INSTALL instructions.

Version 1.2.9beta3 [February 24, 2006]
  Fixed CRCRLF line endings in contrib/visupng/VisualPng.dsp
  Made libpng.pc respect EXEC_PREFIX (D. P. Kreil, J. Bowler)
  Removed reference to pngasmrd.h from Makefile.am
  Renamed CHANGES to ChangeLog.
  Renamed LICENSE to COPYING.
  Renamed ANNOUNCE to NEWS.
  Created AUTHORS file.

Version 1.2.9beta4 [March 3, 2006]
  Changed definition of PKGCONFIG from $prefix/lib to $libdir in configure.ac
  Reverted to filenames LICENSE and ANNOUNCE; removed AUTHORS and COPYING.
  Removed newline from the end of some error and warning messages.
  Removed test for sqrt() from configure.ac and configure.
  Made swap tables in pngtrans.c PNG_CONST (Carlo Bramix).
  Disabled default iTXt support that was inadvertently enabled in
    libpng-1.2.9beta1.
  Added "OS2" to list of systems that don't need underscores, in pnggccrd.c
  Removed libpng version and date from *.c files.

Version 1.2.9beta5 [March 4, 2006]
  Removed trailing blanks from source files.
  Put version and date of latest change in each source file, and changed
    copyright year accordingly.
  More cleanup of configure.ac, Makefile.am, and associated scripts.
  Restored scripts/makefile.elf which was inadvertently deleted.

Version 1.2.9beta6 [March 6, 2006]
  Fixed typo (RELEASE) in configuration files.

Version 1.2.9beta7 [March 7, 2006]
  Removed libpng.vers and libpng.sym from libpng12_la_SOURCES in Makefile.am
  Fixed inconsistent #ifdef's around png_sig_bytes() and png_set_sCAL_s()
    in png.h.
  Updated makefile.elf as suggested by debian.
  Made cosmetic changes to some makefiles, adding LN_SF and other macros.
  Made some makefiles accept "exec_prefix".

Version 1.2.9beta8 [March 9, 2006]
  Fixed some "#if defined (..." which should be "#if defined(..."
    Bug introduced in libpng-1.2.8.
  Fixed inconsistency in definition of png_default_read_data()
  Restored blank that was lost from makefile.sggcc "clean" target in beta7.
  Revised calculation of "current" and "major" for irix in ltmain.sh
  Changed "mkdir" to "MKDIR_P" in some makefiles.
  Separated PNG_EXPAND and PNG_EXPAND_tRNS.
  Added png_set_expand_gray_1_2_4_to_8() and deprecated
    png_set_gray_1_2_4_to_8() which also expands tRNS to alpha.

Version 1.2.9beta9 [March 10, 2006]
  Include "config.h" in pngconf.h when available.
  Added some checks for NULL png_ptr or NULL info_ptr (timeless)

Version 1.2.9beta10 [March 20, 2006]
  Removed extra CR from contrib/visualpng/VisualPng.dsw (Cosmin)
  Made pnggccrd.c PIC-compliant (Christian Aichinger).
  Added makefile.mingw (Wolfgang Glas).
  Revised pngconf.h MMX checking.

Version 1.2.9beta11 [March 22, 2006]
  Fixed out-of-order declaration in pngwrite.c that was introduced in beta9
  Simplified some makefiles by using LIBSO, LIBSOMAJ, and LIBSOVER macros.

Version 1.2.9rc1 [March 31, 2006]
  Defined PNG_USER_PRIVATEBUILD when including "pngusr.h" (Cosmin).
  Removed nonsensical assertion check from pngtest.c (Cosmin).

Version 1.2.9 [April 14, 2006]
  Revised makefile.beos and added "none" selector in ltmain.sh

Version 1.2.10beta1 [April 15, 2006]
  Renamed "config.h" to "png_conf.h" and revised Makefile.am to add
    -DPNG_BUILDING_LIBPNG to compile directive, and modified pngconf.h
    to include png_conf.h only when PNG_BUILDING_LIBPNG is defined.

Version 1.2.10beta2 [April 15, 2006]
  Manually updated Makefile.in and configure.  Changed png_conf.h.in
    back to config.h.

Version 1.2.10beta3 [April 15, 2006]
  Change png_conf.h back to config.h in pngconf.h.

Version 1.2.10beta4 [April 16, 2006]
  Change PNG_BUILDING_LIBPNG to PNG_CONFIGURE_LIBPNG in config/Makefile*.

Version 1.2.10beta5 [April 16, 2006]
  Added a configure check for compiling assembler code in pnggccrd.c

Version 1.2.10beta6 [April 17, 2006]
  Revised the configure check for pnggccrd.c
  Moved -DPNG_CONFIGURE_LIBPNG into @LIBPNG_DEFINES@
  Added @LIBPNG_DEFINES@ to arguments when building libpng.sym

Version 1.2.10beta7 [April 18, 2006]
  Change "exec_prefix=$prefix" to "exec_prefix=$(prefix)" in makefiles.

Version 1.2.10rc1 [April 19, 2006]
  Ensure pngconf.h doesn't define both PNG_USE_PNGGCCRD and PNG_USE_PNGVCRD
  Fixed "LN_FS" typo in makefile.sco and makefile.solaris.

Version 1.2.10rc2 [April 20, 2006]
  Added a backslash between -DPNG_CONFIGURE_LIBPNG and -DPNG_NO_ASSEMBLER_CODE
   in configure.ac and configure
  Made the configure warning about versioned symbols less arrogant.

Version 1.2.10rc3 [April 21, 2006]
  Added a note in libpng.txt that png_set_sig_bytes(8) can be used when
    writing an embedded PNG without the 8-byte signature.
  Revised makefiles and configure to avoid making links to libpng.so.*

Version 1.2.10 [April 23, 2006]
  Reverted configure to "rc2" state.

Version 1.2.11beta1 [May 31, 2006]
  scripts/libpng.pc.in contained "configure" style version info and would
    not work with makefiles.
  The shared-library makefiles were linking to libpng.so.0 instead of
    libpng.so.3 compatibility as the library.

Version 1.2.11beta2 [June 2, 2006]
  Increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
    buffer overflow.
  Fixed bug in example.c (png_set_palette_rgb -> png_set_palette_to_rgb)

Version 1.2.11beta3 [June 5, 2006]
  Prepended "#! /bin/sh" to ltmail.sh and contrib/pngminus/*.sh (Cosmin).
  Removed the accidental leftover Makefile.in~ (Cosmin).
  Avoided potential buffer overflow and optimized buffer in
    png_write_sCAL(), png_write_sCAL_s() (Cosmin).
  Removed the include directories and libraries from CFLAGS and LDFLAGS
    in scripts/makefile.gcc (Nelson A. de Oliveira, Cosmin).

Version 1.2.11beta4 [June 6, 2006]
  Allow zero-length IDAT chunks after the entire zlib datastream, but not
    after another intervening chunk type.

Version 1.0.19rc1, 1.2.11rc1 [June 13, 2006]
  Deleted extraneous square brackets from [config.h] in configure.ac

Version 1.0.19rc2, 1.2.11rc2 [June 14, 2006]
  Added prototypes for PNG_INCH_CONVERSIONS functions to png.h
  Revised INSTALL and autogen.sh
  Fixed typo in several makefiles (-W1 should be -Wl)
  Added typedef for png_int_32 and png_uint_32 on 64-bit systems.

Version 1.0.19rc3, 1.2.11rc3 [June 15, 2006]
  Removed the new typedefs for 64-bit systems (delay until version 1.4.0)
  Added one zero element to png_gamma_shift[] array in pngrtran.c to avoid
    reading out of bounds.

Version 1.0.19rc4, 1.2.11rc4 [June 15, 2006]
  Really removed the new typedefs for 64-bit systems.

Version 1.0.19rc5, 1.2.11rc5 [June 22, 2006]
  Removed png_sig_bytes entry from scripts/pngw32.def

Version 1.0.19, 1.2.11 [June 26, 2006]
  None.

Version 1.0.20, 1.2.12 [June 27, 2006]
  Really increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
    buffer overflow.

Version 1.2.13beta1 [October 2, 2006]
  Removed AC_FUNC_MALLOC from configure.ac
  Work around Intel-Mac compiler bug by setting PNG_NO_MMX_CODE in pngconf.h
  Change "logical" to "bitwise" throughout documentation.
  Detect and fix attempt to write wrong iCCP profile length.

Version 1.0.21, 1.2.13 [November 14, 2006]
  Fix potential buffer overflow in sPLT chunk handler.
  Fix Makefile.am to not try to link to noexistent files.
  Check all exported functions for NULL png_ptr.

Version 1.2.14beta1 [November 17, 2006]
  Relocated three misplaced tests for NULL png_ptr.
  Built Makefile.in with automake-1.9.6 instead of 1.9.2.
  Build configure with autoconf-2.60 instead of 2.59

Version 1.2.14beta2 [November 17, 2006]
  Added some typecasts in png_zalloc().

Version 1.2.14rc1 [November 20, 2006]
  Changed "strtod" to "png_strtod" in pngrutil.c

Version 1.0.22, 1.2.14    [November 27, 2006]
  Added missing "$(srcdir)" in Makefile.am and Makefile.in

Version 1.2.15beta1 [December 3, 2006]
  Generated configure with autoconf-2.61 instead of 2.60
  Revised configure.ac to update libpng.pc and libpng-config.

Version 1.2.15beta2 [December 3, 2006]
  Always export MMX asm functions, just stubs if not building pnggccrd.c

Version 1.2.15beta3 [December 4, 2006]
  Add "png_bytep" typecast to profile while calculating length in pngwutil.c

Version 1.2.15beta4 [December 7, 2006]
  Added scripts/CMakeLists.txt
  Changed PNG_NO_ASSEMBLER_CODE to PNG_NO_MMX_CODE in scripts, like 1.4.0beta

Version 1.2.15beta5 [December 7, 2006]
  Changed some instances of PNG_ASSEMBLER_* to PNG_MMX_* in pnggccrd.c
  Revised scripts/CMakeLists.txt

Version 1.2.15beta6 [December 13, 2006]
  Revised scripts/CMakeLists.txt and configure.ac

Version 1.2.15rc1 [December 18, 2006]
  Revised scripts/CMakeLists.txt

Version 1.2.15rc2 [December 21, 2006]
  Added conditional #undef jmpbuf in pngtest.c to undo #define in AIX headers.
  Added scripts/makefile.nommx

Version 1.2.15rc3 [December 25, 2006]
  Fixed shared library numbering error that was introduced in 1.2.15beta6.

Version 1.2.15rc4 [December 27, 2006]
  Fixed handling of rgb_to_gray when png_ptr->color.gray isn't set.

Version 1.2.15rc5 [December 31, 2006]
  Revised handling of rgb_to_gray.

Version 1.2.15 [January 5, 2007]
  Added some (unsigned long) typecasts in pngtest.c to avoid printing errors.

Version 1.2.16beta1 [January 6, 2007]
  Fix bugs in makefile.nommx

Version 1.2.16beta2 [January 16, 2007]
  Revised scripts/CMakeLists.txt

Version 1.2.16 [January 31, 2007]
  No changes.

Version 1.2.17beta1 [March 6, 2007]
  Revised scripts/CMakeLists.txt to install both shared and static libraries.
  Deleted a redundant line from pngset.c.

Version 1.2.17beta2 [April 26, 2007]
  Relocated misplaced test for png_ptr == NULL in pngpread.c
  Change "==" to "&" for testing PNG_RGB_TO_GRAY_ERR & PNG_RGB_TO_GRAY_WARN
    flags.
  Changed remaining instances of PNG_ASSEMBLER_* to PNG_MMX_*
  Added pngerror() when write_IHDR fails in deflateInit2().
  Added "const" to some array declarations.
  Mention examples of libpng usage in the libpng*.txt and libpng.3 documents.

Version 1.2.17rc1 [May 4, 2007]
  No changes.

Version 1.2.17rc2 [May 8, 2007]
  Moved several PNG_HAVE_* macros out of PNG_INTERNAL because applications
    calling set_unknown_chunk_location() need them.
  Changed transformation flag from PNG_EXPAND_tRNS to PNG_EXPAND in
    png_set_expand_gray_1_2_4_to_8().
  Added png_ptr->unknown_chunk to hold working unknown chunk data, so it
    can be free'ed in case of error.  Revised unknown chunk handling in
    pngrutil.c and pngpread.c to use this structure.

Version 1.2.17rc3 [May 8, 2007]
  Revised symbol-handling in configure script.

Version 1.2.17rc4 [May 10, 2007]
  Revised unknown chunk handling to avoid storing unknown critical chunks.

Version 1.0.25 [May 15, 2007]
Version 1.2.17 [May 15, 2007]
  Added "png_ptr->num_trans=0" before error return in png_handle_tRNS,
    to eliminate a vulnerability (CVE-2007-2445, CERT VU#684664)

Version 1.0.26 [May 15, 2007]
Version 1.2.18 [May 15, 2007]
  Reverted the libpng-1.2.17rc3 change to symbol-handling in configure script

Version 1.2.19beta1 [May 18, 2007]
  Changed "const static" to "static PNG_CONST" everywhere, mostly undoing
    change of libpng-1.2.17beta2.  Changed other "const" to "PNG_CONST"
  Changed some handling of unused parameters, to avoid compiler warnings.
    "if (unused == NULL) return;" becomes "unused = unused".

Version 1.2.19beta2 [May 18, 2007]
  Only use the valid bits of tRNS value in png_do_expand() (Brian Cartier)

Version 1.2.19beta3 [May 19, 2007]
  Add some "png_byte" typecasts in png_check_keyword() and write new_key
  instead of key in zTXt chunk (Kevin Ryde).

Version 1.2.19beta4 [May 21, 2007]
  Add png_snprintf() function and use it in place of sprint() for improved
    defense against buffer overflows.

Version 1.2.19beta5 [May 21, 2007]
  Fixed png_handle_tRNS() to only use the valid bits of tRNS value.
  Changed handling of more unused parameters, to avoid compiler warnings.
  Removed some PNG_CONST in pngwutil.c to avoid compiler warnings.

Version 1.2.19beta6 [May 22, 2007]
  Added some #ifdef PNG_MMX_CODE_SUPPORTED where needed in pngvcrd.c
  Added a special "_MSC_VER" case that defines png_snprintf to _snprintf

Version 1.2.19beta7 [May 22, 2007]
  Squelched png_squelch_warnings() in pnggccrd.c and added
    an #ifdef PNG_MMX_CODE_SUPPORTED block around the declarations that caused
    the warnings that png_squelch_warnings was squelching.

Version 1.2.19beta8 [May 22, 2007]
  Removed __MMX__ from test in pngconf.h.

Version 1.2.19beta9 [May 23, 2007]
  Made png_squelch_warnings() available via PNG_SQUELCH_WARNINGS macro.
  Revised png_squelch_warnings() so it might work.
  Updated makefile.sgcc and makefile.solaris; added makefile.solaris-x86.

Version 1.2.19beta10 [May 24, 2007]
  Resquelched png_squelch_warnings(), use "__attribute__((used))" instead.

Version 1.4.0beta1 [April 20, 2006]
  Enabled iTXt support (changes png_struct, thus requires so-number change).
  Cleaned up PNG_ASSEMBLER_CODE_SUPPORTED vs PNG_MMX_CODE_SUPPORTED
  Eliminated PNG_1_0_X and PNG_1_2_X macros.
  Removed deprecated functions png_read_init, png_write_init, png_info_init,
    png_permit_empty_plte, png_set_gray_1_2_4_to_8, png_check_sig, and
    removed the deprecated macro PNG_MAX_UINT.
  Moved "PNG_INTERNAL" parts of png.h and pngconf.h into pngintrn.h
  Removed many WIN32_WCE #ifdefs (Cosmin).
  Reduced dependency on C-runtime library when on Windows (Simon-Pierre)
  Replaced sprintf() with png_sprintf() (Simon-Pierre)

Version 1.4.0beta2 [April 20, 2006]
  Revised makefiles and configure to avoid making links to libpng.so.*
  Moved some leftover MMX-related defines from pngconf.h to pngintrn.h
  Updated scripts/pngos2.def, pngw32.def, and projects/wince/png32ce.def

Version 1.4.0beta3 [May 10, 2006]
  Updated scripts/pngw32.def to comment out MMX functions.
  Added PNG_NO_GET_INT_32 and PNG_NO_SAVE_INT_32 macros.
  Scripts/libpng.pc.in contained "configure" style version info and would
    not work with makefiles.
  Revised pngconf.h and added pngconf.h.in, so makefiles and configure can
    pass defines to libpng and applications.

Version 1.4.0beta4 [May 11, 2006]
  Revised configure.ac, Makefile.am, and many of the makefiles to write
    their defines in pngconf.h.

Version 1.4.0beta5 [May 15, 2006]
  Added a missing semicolon in Makefile.am and Makefile.in
  Deleted extraneous square brackets from configure.ac

Version 1.4.0beta6 [June 2, 2006]
  Increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
    buffer overflow.
  Changed sonum from 0 to 1.
  Removed unused prototype for png_check_sig() from png.h

Version 1.4.0beta7 [June 16, 2006]
  Exported png_write_sig (Cosmin).
  Optimized buffer in png_handle_cHRM() (Cosmin).
  Set pHYs = 2835 x 2835 pixels per meter, and added
    sCAL = 0.352778e-3 x 0.352778e-3 meters, in pngtest.png (Cosmin).
  Added png_set_benign_errors(), png_benign_error(), png_chunk_benign_error().
  Added typedef for png_int_32 and png_uint_32 on 64-bit systems.
  Added "(unsigned long)" typecast on png_uint_32 variables in printf lists.

Version 1.4.0beta8 [June 22, 2006]
  Added demonstration of user chunk support in pngtest.c, to support the
    public sTER chunk and a private vpAg chunk.

Version 1.4.0beta9 [July 3, 2006]
  Removed ordinals from scripts/pngw32.def and removed png_info_int and
    png_set_gray_1_2_4_to_8 entries.
  Inline call of png_get_uint_32() in png_get_uint_31().
  Use png_get_uint_31() to get vpAg width and height in pngtest.c
  Removed WINCE and Netware projects.
  Removed standalone Y2KINFO file.

Version 1.4.0beta10 [July 12, 2006]
  Eliminated automatic copy of pngconf.h to pngconf.h.in from configure and
    some makefiles, because it was not working reliably.  Instead, distribute
    pngconf.h.in along with pngconf.h and cause configure and some of the
    makefiles to update pngconf.h from pngconf.h.in.
  Added pngconf.h to DEPENDENCIES in Makefile.am

Version 1.4.0beta11 [August 19, 2006]
  Removed AC_FUNC_MALLOC from configure.ac.
  Added a warning when writing iCCP profile with mismatched profile length.
  Patched pnggccrd.c to assemble on x86_64 platforms.
  Moved chunk header reading into a separate function png_read_chunk_header()
    in pngrutil.c.  The chunk header (len+sig) is now serialized in a single
    operation (Cosmin).
  Implemented support for I/O states. Added png_ptr member io_state, and
    functions png_get_io_chunk_name() and png_get_io_state() in pngget.c
    (Cosmin).
  Added png_get_io_chunk_name and png_get_io_state to scripts/*.def (Cosmin).
  Renamed scripts/pngw32.* to scripts/pngwin.* (Cosmin).
  Removed the include directories and libraries from CFLAGS and LDFLAGS
    in scripts/makefile.gcc (Cosmin).
  Used png_save_uint_32() to set vpAg width and height in pngtest.c (Cosmin).
  Cast to proper type when getting/setting vpAg units in pngtest.c (Cosmin).
  Added pngintrn.h to the Visual C++ projects (Cosmin).
  Removed scripts/list (Cosmin).
  Updated copyright year in scripts/pngwin.def (Cosmin).
  Removed PNG_TYPECAST_NULL and used standard NULL consistently (Cosmin).
  Disallowed the user to redefine png_size_t, and enforced a consistent use
    of png_size_t across libpng (Cosmin).
  Changed the type of png_ptr->rowbytes, PNG_ROWBYTES() and friends
    to png_size_t (Cosmin).
  Removed png_convert_size() and replaced png_sizeof with sizeof (Cosmin).
  Removed some unnecessary type casts (Cosmin).
  Changed prototype of png_get_compression_buffer_size() and
    png_set_compression_buffer_size() to work with png_size_t instead of
    png_uint_32 (Cosmin).
  Removed png_memcpy_check() and png_memset_check() (Cosmin).
  Fixed a typo (png_byte --> png_bytep) in libpng.3 and libpng.txt (Cosmin).
  Clarified that png_zalloc() does not clear the allocated memory,
    and png_zalloc() and png_zfree() cannot be PNGAPI (Cosmin).
  Renamed png_mem_size_t to png_alloc_size_t, fixed its definition in
    pngconf.h, and used it in all memory allocation functions (Cosmin).
  Renamed pngintrn.h to pngpriv.h, added a comment at the top of the file
    mentioning that the symbols declared in that file are private, and
    updated the scripts and the Visual C++ projects accordingly (Cosmin).
  Removed circular references between pngconf.h and pngconf.h.in in
    scripts/makefile.vc*win32 (Cosmin).
  Removing trailing '.' from the warning and error messages (Cosmin).
  Added pngdefs.h that is built by makefile or configure, instead of
    pngconf.h.in (Glenn).
  Detect and fix attempt to write wrong iCCP profile length.

Version 1.4.0beta12 [October 19, 2006]
  Changed "logical" to "bitwise" in the documentation.
  Work around Intel-Mac compiler bug by setting PNG_NO_MMX_CODE in pngconf.h
  Add a typecast to stifle compiler warning in pngrutil.c

Version 1.4.0beta13 [November 10, 2006]
  Fix potential buffer overflow in sPLT chunk handler.
  Fix Makefile.am to not try to link to noexistent files.

Version 1.4.0beta14 [November 15, 2006]
  Check all exported functions for NULL png_ptr.

Version 1.4.0beta15 [November 17, 2006]
  Relocated two misplaced tests for NULL png_ptr.
  Built Makefile.in with automake-1.9.6 instead of 1.9.2.
  Build configure with autoconf-2.60 instead of 2.59
  Add "install: all" in Makefile.am so "configure; make install" will work.

Version 1.4.0beta16 [November 17, 2006]
  Added a typecast in png_zalloc().

Version 1.4.0beta17 [December 4, 2006]
  Changed "new_key[79] = '\0';" to "(*new_key)[79] = '\0';" in pngwutil.c
  Add "png_bytep" typecast to profile while calculating length in pngwutil.c

Version 1.4.0beta18 [December 7, 2006]
  Added scripts/CMakeLists.txt

Version 1.4.0beta19 [May 16, 2007]
  Revised scripts/CMakeLists.txt
  Rebuilt configure and Makefile.in with newer tools.
  Added conditional #undef jmpbuf in pngtest.c to undo #define in AIX headers.
  Added scripts/makefile.nommx

Version 1.4.0beta20 [July 9, 2008]
  Moved several PNG_HAVE_* macros from pngpriv.h to png.h because applications
    calling set_unknown_chunk_location() need them.
  Moved several macro definitions from pngpriv.h to pngconf.h
  Merge with changes to the 1.2.X branch, as of 1.2.30beta04.
  Deleted all use of the MMX assembler code and Intel-licensed optimizations.
  Revised makefile.mingw

Version 1.4.0beta21 [July 21, 2008]
  Moved local array "chunkdata" from pngrutil.c to the png_struct, so
    it will be freed by png_read_destroy() in case of a read error (Kurt
    Christensen).

Version 1.4.0beta22 [July 21, 2008]
  Change "purpose" and "buffer" to png_ptr->chunkdata to avoid memory leaking.

Version 1.4.0beta23 [July 22, 2008]
  Change "chunkdata = NULL" to "png_ptr->chunkdata = NULL" several places in
    png_decompress_chunk().

Version 1.4.0beta24 [July 25, 2008]
  Change all remaining "chunkdata" to "png_ptr->chunkdata" in
    png_decompress_chunk(), and remove "chunkdata" from parameter list.
  Put a call to png_check_chunk_name() in png_read_chunk_header().
  Revised png_check_chunk_name() to reject a name with a lowercase 3rd byte.
  Removed two calls to png_check_chunk_name() occuring later in the process.
  Define PNG_NO_ERROR_NUMBERS by default in pngconf.h

Version 1.4.0beta25 [July 30, 2008]
  Added a call to png_check_chunk_name() in pngpread.c
  Reverted png_check_chunk_name() to accept a name with a lowercase 3rd byte.
  Added png_push_have_buffer() function to pngpread.c
  Eliminated PNG_BIG_ENDIAN_SUPPORTED and associated png_get_* macros.
  Made inline expansion of png_get_*() optional with PNG_USE_READ_MACROS.
  Eliminated all PNG_USELESS_TESTS and PNG_CORRECT_PALETTE_SUPPORTED code.
  Synced contrib directory and configure files with libpng-1.2.30beta06.
  Eliminated no-longer-used pngdefs.h (but it's still built in the makefiles)
  Relocated a misplaced "#endif /* PNG_NO_WRITE_FILTER */" in pngwutil.c

Version 1.4.0beta26 [August 4, 2008]
  Removed png_push_have_buffer() function in pngpread.c.  It increased the
    compiled library size slightly.
  Changed "-Wall" to "-W -Wall" in the CFLAGS in all makefiles (Cosmin Truta)
  Declared png_ptr "volatile" in pngread.c and pngwrite.c to avoid warnings.
  Updated contrib/visupng/cexcept.h to version 2.0.1
  Added PNG_LITERAL_CHARACTER macros for #, [, and ].

Version 1.4.0beta27 [August 5, 2008]
  Revised usage of PNG_LITERAL_SHARP in pngerror.c.
  Moved newline character from individual png_debug messages into the
    png_debug macros.
  Allow user to #define their own png_debug, png_debug1, and png_debug2.

Version 1.4.0beta28 [August 5, 2008]
  Revised usage of PNG_LITERAL_SHARP in pngerror.c.
  Added PNG_STRING_NEWLINE macro

Version 1.4.0beta29 [August 9, 2008]
  Revised usage of PNG_STRING_NEWLINE to work on non-ISO compilers.
  Added PNG_STRING_COPYRIGHT macro.
  Added non-ISO versions of png_debug macros.

Version 1.4.0beta30 [August 14, 2008]
  Added premultiplied alpha feature (Volker Wiendl).

Version 1.4.0beta31 [August 18, 2008]
  Moved png_set_premultiply_alpha from pngtrans.c to pngrtran.c
  Removed extra crc check at the end of png_handle_cHRM().  Bug introduced
    in libpng-1.4.0beta20.

Version 1.4.0beta32 [August 19, 2008]
  Added PNG_WRITE_FLUSH_SUPPORTED block around new png_flush() call.
  Revised PNG_NO_STDIO version of png_write_flush()

Version 1.4.0beta33 [August 20, 2008]
  Added png_get|set_chunk_cache_max() to limit the total number of sPLT,
    text, and unknown chunks that can be stored.

Version 1.4.0beta34 [September 6, 2008]
  Shortened tIME_string to 29 bytes in pngtest.c
  Fixed off-by-one error introduced in png_push_read_zTXt() function in
    libpng-1.2.30beta04/pngpread.c (Harald van Dijk)

Version 1.4.0beta35 [October 6, 2008]
  Changed "trans_values" to "trans_color".
  Changed so-number from 0 to 14.  Some OS do not like 0.
  Revised makefile.darwin to fix shared library numbering.
  Change png_set_gray_1_2_4_to_8() to png_set_expand_gray_1_2_4_to_8()
    in example.c (debian bug report)

Version 1.4.0beta36 [October 25, 2008]
  Sync with tEXt vulnerability fix in libpng-1.2.33rc02.

Version 1.4.0beta37 [November 13, 2008]
  Added png_check_cHRM in png.c and moved checking from pngget.c, pngrutil.c,
    and pngwrite.c

Version 1.4.0beta38 [November 22, 2008]
  Added check for zero-area RGB cHRM triangle in png_check_cHRM() and
    png_check_cHRM_fixed().

Version 1.4.0beta39 [November 23, 2008]
  Revised png_warning() to write its message on standard output by default
    when warning_fn is NULL.

Version 1.4.0beta40 [November 24, 2008]
  Eliminated png_check_cHRM().  Instead, always use png_check_cHRM_fixed().
  In png_check_cHRM_fixed(), ensure white_y is > 0, and removed redundant
    check for all-zero coordinates that is detected by the triangle check.

Version 1.4.0beta41 [November 26, 2008]
  Fixed string vs pointer-to-string error in png_check_keyword().
  Rearranged test expressions in png_check_cHRM_fixed() to avoid internal
    overflows.
  Added PNG_NO_CHECK_cHRM conditional.

Version 1.4.0beta42, 43 [December 1, 2008]
  Merge png_debug with version 1.2.34beta04.

Version 1.4.0beta44 [December 6, 2008]
  Removed redundant check for key==NULL before calling png_check_keyword()
    to ensure that new_key gets initialized and removed extra warning
    (Merge with version 1.2.34beta05 -- Arvan Pritchard).

Version 1.4.0beta45 [December 9, 2008]
  In png_write_png(), respect the placement of the filler bytes in an earlier
    call to png_set_filler() (Jim Barry).

Version 1.4.0beta46 [December 10, 2008]
  Undid previous change and added PNG_TRANSFORM_STRIP_FILLER_BEFORE and
    PNG_TRANSFORM_STRIP_FILLER_AFTER conditionals and deprecated
    PNG_TRANSFORM_STRIP_FILLER (Jim Barry).

Version 1.4.0beta47 [December 15, 2008]
  Support for dithering was disabled by default, because it has never
    been well tested and doesn't work very well.  The code has not
    been removed, however, and can be enabled by building libpng with
    PNG_READ_DITHER_SUPPORTED defined.

Version 1.4.0beta48 [February 14, 2009]
  Added new exported function png_calloc().
  Combined several instances of png_malloc(); png_memset() into png_calloc().
  Removed prototype for png_freeptr() that was added in libpng-1.4.0beta24
    but was never defined.

Version 1.4.0beta49 [February 28, 2009]
  Added png_fileno() macro to pngconf.h, used in pngwio.c
  Corrected order of #ifdef's in png_debug definition in png.h
  Fixed bug introduced in libpng-1.4.0beta48 with the memset arguments
    for pcal_params.
  Fixed order of #ifdef directives in the png_debug defines in png.h
    (bug introduced in libpng-1.2.34/1.4.0beta29).
  Revised comments in png_set_read_fn() and png_set_write_fn().

Version 1.4.0beta50 [March 18, 2009]
  Use png_calloc() instead of png_malloc() to allocate big_row_buf when
    reading an interlaced file, to avoid a possible UMR.
  Undid revision of PNG_NO_STDIO version of png_write_flush().  Users
    having trouble with fflush() can build with PNG_NO_WRITE_FLUSH defined
    or supply their own flush_fn() replacement.
  Revised libpng*.txt and png.h documentation about use of png_write_flush()
    and png_set_write_fn().
  Removed fflush() from pngtest.c.
  Added "#define PNG_NO_WRITE_FLUSH" to contrib/pngminim/encoder/pngusr.h

Version 1.4.0beta51 [March 21, 2009]
  Removed new png_fileno() macro from pngconf.h .

Version 1.4.0beta52 [March 27, 2009]
  Relocated png_do_chop() ahead of building gamma tables in pngrtran.c
    This avoids building 16-bit gamma tables unnecessarily.
  Removed fflush() from pngtest.c.
  Added "#define PNG_NO_WRITE_FLUSH" to contrib/pngminim/encoder/pngusr.h
  Added a section on differences between 1.0.x and 1.2.x to libpng.3/libpng.txt

Version 1.4.0beta53 [April 1, 2009]
  Removed some remaining MMX macros from pngpriv.h
  Fixed potential memory leak of "new_name" in png_write_iCCP() (Ralph Giles)

Version 1.4.0beta54 [April 13, 2009]
  Added "ifndef PNG_SKIP_SETJMP_CHECK" block in pngconf.h to allow
    application code writers to bypass the check for multiple inclusion
    of setjmp.h when they know that it is safe to ignore the situation.
  Eliminated internal use of setjmp() in pngread.c and pngwrite.c
  Reordered ancillary chunks in pngtest.png to be the same as what
    pngtest now produces, and made some cosmetic changes to pngtest output.
  Eliminated deprecated png_read_init_3() and png_write_init_3() functions.

Version 1.4.0beta55 [April 15, 2009]
  Simplified error handling in pngread.c and pngwrite.c by putting
    the new png_read_cleanup() and png_write_cleanup() functions inline.

Version 1.4.0beta56 [April 25, 2009]
  Renamed "user_chunk_data" to "my_user_chunk_data" in pngtest.c to suppress
    "shadowed declaration" warning from gcc-4.3.3.
  Renamed "gamma" to "png_gamma" in pngset.c to avoid "shadowed declaration"
    warning about a global "gamma" variable in math.h on some platforms.

Version 1.4.0beta57 [May 2, 2009]
  Removed prototype for png_freeptr() that was added in libpng-1.4.0beta24
    but was never defined (again).
  Rebuilt configure scripts with autoconf-2.63 instead of 2.62
  Removed pngprefs.h and MMX from makefiles

Version 1.4.0beta58 [May 14, 2009]
  Changed pngw32.def to pngwin.def in makefile.mingw (typo was introduced
    in beta57).
  Clarified usage of sig_bit versus sig_bit_p in example.c (Vincent Torri)

Version 1.4.0beta59 [May 15, 2009]
  Reformated sources in libpng style (3-space intentation, comment format)
  Fixed typo in libpng docs (PNG_FILTER_AVE should be PNG_FILTER_AVG)
  Added sections about the git repository and our coding style to the
    documentation
  Relocated misplaced #endif in pngwrite.c, sCAL chunk handler.

Version 1.4.0beta60 [May 19, 2009]
  Conditionally compile png_read_finish_row() which is not used by
    progressive readers.
  Added contrib/pngminim/preader to demonstrate building minimal progressive
    decoder, based on contrib/gregbook with embedded libpng and zlib.

Version 1.4.0beta61 [May 20, 2009]
  In contrib/pngminim/*, renamed "makefile.std" to "makefile", since there
    is only one makefile in those directories, and revised the README files
    accordingly.
  More reformatting of comments, mostly to capitalize sentences.

Version 1.4.0beta62 [June 2, 2009]
  Added "#define PNG_NO_WRITE_SWAP" to contrib/pngminim/encoder/pngusr.h
    and "define PNG_NO_READ_SWAP" to decoder/pngusr.h and preader/pngusr.h
  Reformatted several remaining "else statement" into two lines.
  Added a section to the libpng documentation about using png_get_io_ptr()
    in configure scripts to detect the presence of libpng.

Version 1.4.0beta63 [June 15, 2009]
  Revised libpng*.txt and libpng.3 to mention calling png_set_IHDR()
    multiple times and to specify the sample order in the tRNS chunk,
    because the ISO PNG specification has a typo in the tRNS table.
  Changed several PNG_UNKNOWN_CHUNK_SUPPORTED to
    PNG_HANDLE_AS_UNKNOWN_SUPPORTED, to make the png_set_keep mechanism
    available for ignoring known chunks even when not saving unknown chunks.
  Adopted preference for consistent use of "#ifdef" and "#ifndef" versus
    "#if defined()" and "if !defined()" where possible.

Version 1.4.0beta64 [June 24, 2009]
  Eliminated PNG_LEGACY_SUPPORTED code.
  Moved the various unknown chunk macro definitions outside of the
     PNG_READ|WRITE_ANCILLARY_CHUNK_SUPPORTED blocks.

Version 1.4.0beta65 [June 26, 2009]
  Added a reference to the libpng license in each file.

Version 1.4.0beta66 [June 27, 2009]
  Refer to the libpng license instead of the libpng license in each file.

Version 1.4.0beta67 [July 6, 2009]
  Relocated INVERT_ALPHA within png_read_png() and png_write_png().
  Added high-level API transform PNG_TRANSFORM_GRAY_TO_RGB.
  Added an "xcode" project to the projects directory (Alam Arias).

Version 1.4.0beta68 [July 19, 2009]
  Avoid some tests in filter selection in pngwutil.c

Version 1.4.0beta69 [July 25, 2009]
  Simplified the new filter-selection test.  This runs faster in the
    common "PNG_ALL_FILTERS" and PNG_FILTER_NONE cases.
  Removed extraneous declaration from the new call to png_read_gray_to_rgb()
    (bug introduced in libpng-1.4.0beta67).
  Fixed up xcode project (Alam Arias)
  Added a prototype for png_64bit_product() in png.c

Version 1.4.0beta70 [July 27, 2009]
  Avoid a possible NULL dereference in debug build, in png_set_text_2().
    (bug introduced in libpng-0.95, discovered by Evan Rouault)

Version 1.4.0beta71 [July 29, 2009]
  Rebuilt configure scripts with autoconf-2.64.

Version 1.4.0beta72 [August 1, 2009]
  Replaced *.tar.lzma with *.tar.xz in distribution.  Get the xz codec
    from <http://tukaani.org/xz>.

Version 1.4.0beta73 [August 1, 2009]
  Reject attempt to write iCCP chunk with negative embedded profile length
    (JD Chen)

Version 1.4.0beta74 [August 8, 2009]
  Changed png_ptr and info_ptr member "trans" to "trans_alpha".

Version 1.4.0beta75 [August 21, 2009]
  Removed an extra png_debug() recently added to png_write_find_filter().
  Fixed incorrect #ifdef in pngset.c regarding unknown chunk support.

Version 1.4.0beta76 [August 22, 2009]
  Moved an incorrectly located test in png_read_row() in pngread.c

Version 1.4.0beta77 [August 27, 2009]
  Removed lpXYZ.tar.bz2 (with CRLF), KNOWNBUG, libpng-x.y.z-KNOWNBUG.txt,
    and the "noconfig" files from the distribution.
  Moved CMakeLists.txt from scripts into the main libpng directory.
  Various bugfixes and improvements to CMakeLists.txt (Philip Lowman)

Version 1.4.0beta78 [August 31, 2009]
  Converted all PNG_NO_* tests to PNG_*_SUPPORTED everywhere except pngconf.h
  Eliminated PNG_NO_FREE_ME and PNG_FREE_ME_SUPPORTED macros.
  Use png_malloc plus a loop instead of png_calloc() to initialize
    row_pointers in png_read_png().

Version 1.4.0beta79 [September 1, 2009]
  Eliminated PNG_GLOBAL_ARRAYS and PNG_LOCAL_ARRAYS; always use local arrays.
  Eliminated PNG_CALLOC_SUPPORTED macro and always provide png_calloc().

Version 1.4.0beta80 [September 17, 2009]
  Removed scripts/libpng.icc
  Changed typecast of filler from png_byte to png_uint_16 in png_set_filler().
    (Dennis Gustafsson)
  Fixed typo introduced in beta78 in pngtest.c ("#if def " should be "#ifdef ")

Version 1.4.0beta81 [September 23, 2009]
  Eliminated unused PNG_FLAG_FREE_* defines from pngpriv.h
  Expanded TAB characters in pngrtran.c
  Removed PNG_CONST from all "PNG_CONST PNG_CHNK" declarations to avoid
    compiler complaints about doubly declaring things "const".
  Changed all "#if [!]defined(X)" to "if[n]def X" where possible.
  Eliminated unused png_ptr->row_buf_size

Version 1.4.0beta82 [September 25, 2009]
  Moved redundant IHDR checking into new png_check_IHDR() in png.c
    and report all errors found in the IHDR data.
  Eliminated useless call to png_check_cHRM() from pngset.c

Version 1.4.0beta83 [September 25, 2009]
  Revised png_check_IHDR() to eliminate bogus complaint about filter_type.

Version 1.4.0beta84 [September 30, 2009]
  Fixed some inconsistent indentation in pngconf.h
  Revised png_check_IHDR() to add a test for width variable less than 32-bit.

Version 1.4.0beta85 [October 1, 2009]
  Revised png_check_IHDR() again, to check info_ptr members instead of
    the contents of the returned parameters.

Version 1.4.0beta86 [October 9, 2009]
  Updated the "xcode" project (Alam Arias).
  Eliminated a shadowed declaration of "pp" in png_handle_sPLT().

Version 1.4.0rc01 [October 19, 2009]
  Trivial cosmetic changes.

Version 1.4.0beta87 [October 30, 2009]
  Moved version 1.4.0 back into beta.

Version 1.4.0beta88 [October 30, 2009]
  Revised libpng*.txt section about differences between 1.2.x and 1.4.0
    because most of the new features have now been ported back to 1.2.41

Version 1.4.0beta89 [November 1, 2009]
  More bugfixes and improvements to CMakeLists.txt (Philip Lowman)
  Removed a harmless extra png_set_invert_alpha() from pngwrite.c
  Apply png_user_chunk_cache_max within png_decompress_chunk().
  Merged libpng-1.2.41.txt with libpng-1.4.0.txt where appropriate.

Version 1.4.0beta90 [November 2, 2009]
  Removed all remaining WIN32_WCE #ifdefs except those involving the
    time.h "tm" structure

Version 1.4.0beta91 [November 3, 2009]
  Updated scripts/pngw32.def and projects/wince/png32ce.def
  Copied projects/wince/png32ce.def to the scripts directory.
  Added scripts/makefile.wce
  Patched ltmain.sh for wince support.
  Added PNG_CONVERT_tIME_SUPPORTED macro.

Version 1.4.0beta92 [November 4, 2009]
  Make inclusion of time.h in pngconf.h depend on PNG_CONVERT_tIME_SUPPORTED
  Make #define PNG_CONVERT_tIME_SUPPORTED depend on PNG_WRITE_tIME_SUPPORTED
  Revised libpng*.txt to describe differences from 1.2.40 to 1.4.0 (instead
    of differences from 1.2.41 to 1.4.0)

Version 1.4.0beta93 [November 7, 2009]
  Added PNG_DEPSTRUCT, PNG_DEPRECATED, PNG_USE_RESULT, PNG_NORETURN, and
    PNG_ALLOCATED macros to detect deprecated direct access to the
    png_struct or info_struct members and other deprecated usage in
    applications (John Bowler).
  Updated scripts/makefile* to add "-DPNG_CONFIGURE_LIBPNG" to CFLAGS,
    to prevent warnings about direct access to png structs by libpng
    functions while building libpng.  They need to be tested, especially
    those using compilers other than gcc.
  Updated projects/visualc6 and visualc71 with "/d PNG_CONFIGURE_LIBPNG".
    They should work but still need to be updated to remove
    references to pnggccrd.c or pngvcrd.c and ASM building.
  Added README.txt to the beos, cbuilder5, netware, and xcode projects warning
    that they need to be updated, to remove references to pnggccrd.c and
    pngvcrd.c and to depend on pngpriv.h
  Removed three direct references to read_info_ptr members in pngtest.c
    that were detected by the new PNG_DEPSTRUCT macro.
  Moved the png_debug macro definitions and the png_read_destroy(),
    png_write_destroy() and png_far_to_near() prototypes from png.h
    to pngpriv.h (John Bowler)
  Moved the synopsis lines for png_read_destroy(), png_write_destroy()
    png_debug(), png_debug1(), and png_debug2() from libpng.3 to libpngpf.3.

Version 1.4.0beta94 [November 9, 2009]
  Removed the obsolete, unused pnggccrd.c and pngvcrd.c files.
  Updated CMakeLists.txt to add "-DPNG_CONFIGURE_LIBPNG" to the definitions.
  Removed dependency of pngtest.o on pngpriv.h in the makefiles.
  Only #define PNG_DEPSTRUCT, etc. in pngconf.h if not already defined.

Version 1.4.0beta95 [November 10, 2009]
  Changed png_check_sig() to !png_sig_cmp() in contrib programs.
  Added -DPNG_CONFIGURE_LIBPNG to contrib/pngminm/*/makefile
  Changed png_check_sig() to !png_sig_cmp() in contrib programs.
  Corrected the png_get_IHDR() call in contrib/gregbook/readpng2.c
  Changed pngminim/*/gather.sh to stop trying to remove pnggccrd.c and pngvcrd.c
  Added dependency on pngpriv.h in contrib/pngminim/*/makefile

Version 1.4.0beta96 [November 12, 2009]
  Renamed scripts/makefile.wce to scripts/makefile.cegcc
  Revised Makefile.am to use libpng.sys while building libpng.so
    so that only PNG_EXPORT functions are exported.
  Removed the deprecated png_check_sig() function/macro.
  Removed recently removed function names from scripts/*.def
  Revised pngtest.png to put chunks in the same order written by pngtest
    (evidently the same change made in libpng-1.0beta54 was lost).
  Added PNG_PRIVATE macro definition in pngconf.h for possible future use.

Version 1.4.0beta97 [November 13, 2009]
  Restored pngtest.png to the libpng-1.4.0beta7 version.
  Removed projects/beos and netware.txt; no one seems to be supporting them.
  Revised Makefile.in

Version 1.4.0beta98 [November 13, 2009]
  Added the "xcode" project to zip distributions,
  Fixed a typo in scripts/pngwin.def introduced in beta97.

Version 1.4.0beta99 [November 14, 2009]
  Moved libpng-config.in and libpng.pc-configure.in out of the scripts
    directory, to libpng-config.in and libpng-pc.in, respectively, and
    modified Makefile.am and configure.ac accordingly.  Now "configure"
    needs nothing from the "scripts" directory.
  Avoid redefining PNG_CONST in pngconf.h

Version 1.4.0beta100 [November 14, 2009]
  Removed ASM builds from projects/visualc6 and projects/visualc71
  Removed scripts/makefile.nommx and makefile.vcawin32
  Revised CMakeLists.txt to account for new location of libpng-config.in
    and libpng-pc.in
  Updated INSTALL to reflect removal and relocation of files.

Version 1.4.0beta101 [November 14, 2009]
  Restored the binary files (*.jpg, *.png, some project files) that were
    accidentally deleted from the zip and 7z distributions when the xcode
    project was added.

Version 1.4.0beta102 [November 18, 2009]
  Added libpng-config.in and libpng-pc.in to the zip and 7z distributions.
  Fixed a typo in projects/visualc6/pngtest.dsp, introduced in beta100.
  Moved descriptions of makefiles and other scripts out of INSTALL into
    scripts/README.txt
  Updated the copyright year in scripts/pngwin.rc from 2006 to 2009.

Version 1.4.0beta103 [November 21, 2009]
  Removed obsolete comments about ASM from projects/visualc71/README_zlib.txt
  Align row_buf on 16-byte boundary in memory.
  Restored the PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED guard around the call
    to png_flush() after png_write_IEND().  See 1.4.0beta32, 1.4.0beta50
    changes above and 1.2.30, 1.2.30rc01 and rc03 in 1.2.41 CHANGES.  Someone
    needs this feature.
  Make the 'png_jmpbuf' macro expand to a call that records the correct
    longjmp function as well as returning a pointer to the setjmp
    jmp_buf buffer, and marked direct access to jmpbuf 'deprecated'.
    (John Bowler)

Version 1.4.0beta104 [November 22, 2009]
  Removed png_longjmp_ptr from scripts/*.def and libpng.3
  Rebuilt configure scripts with autoconf-2.65

Version 1.4.0beta105 [November 25, 2009]
  Use fast integer PNG_DIVIDE_BY_255() or PNG_DIVIDE_BY_65535()
    to accomplish alpha premultiplication when
    PNG_READ_COMPOSITE_NODIV_SUPPORTED is defined.
  Changed "/255" to "/255.0" in background calculations to make it clear
    that the 255 is used as a double.

Version 1.4.0beta106 [November 27, 2009]
  Removed premultiplied alpha feature.

Version 1.4.0beta107 [December 4, 2009]
  Updated README
  Added "#define PNG_NO_PEDANTIC_WARNINGS" in the libpng source files.
  Removed "-DPNG_CONFIGURE_LIBPNG" from the makefiles and projects.
  Revised scripts/makefile.netbsd, makefile.openbsd, and makefile.sco
    to put png.h and pngconf.h in $prefix/include, like the other scripts,
    instead of in $prefix/include/libpng.  Also revised makefile.sco
    to put them in $prefix/include/libpng15 instead of in
    $prefix/include/libpng/libpng15.

Version 1.4.0beta108 [December 11, 2009]
  Removed leftover "-DPNG_CONFIGURE_LIBPNG" from contrib/pngminim/*/makefile
  Relocated png_do_chop() to its original position in pngrtran.c; the
    change in version 1.2.41beta08 caused transparency to be handled wrong
    in some 16-bit datastreams (Yusaku Sugai).

Version 1.4.0beta109 [December 13, 2009]
  Added "bit_depth" parameter to the private png_build_gamma_table() function.
  Pass bit_depth=8 to png_build_gamma_table() when bit_depth is 16 but the
    PNG_16_TO_8 transform has been set, to avoid unnecessary build of 16-bit
    tables.

Version 1.4.0rc02 [December 20, 2009]
  Declared png_cleanup_needed "volatile" in pngread.c and pngwrite.c

Version 1.4.0rc03 [December 22, 2009]
  Renamed libpng-pc.in back to libpng.pc.in and revised CMakeLists.txt
    (revising the change in 1.4.0beta99)

Version 1.4.0rc04 [December 25, 2009]
  Swapped PNG_UNKNOWN_CHUNKS_SUPPORTED and PNG_HANDLE_AS_UNKNOWN_SUPPORTED
    in pngset.c to be consistent with other changes in version 1.2.38.

Version 1.4.0rc05 [December 25, 2009]
  Changed "libpng-pc.in" to "libpng.pc.in" in configure.ac, configure, and
    Makefile.in to be consistent with changes in libpng-1.4.0rc03

Version 1.4.0rc06 [December 29, 2009]
  Reverted the gamma_table changes from libpng-1.4.0beta109.
  Fixed some indentation errors.

Version 1.4.0rc07 [January 1, 2010]
  Revised libpng*.txt and libpng.3 about 1.2.x->1.4.x differences.
  Use png_calloc() instead of png_malloc(); png_memset() in pngrutil.c
  Update copyright year to 2010.

Version 1.4.0rc08 [January 2, 2010]
  Avoid deprecated references to png_ptr-io_ptr and png_ptr->error_ptr
    in pngtest.c

Version 1.4.0 [January 3, 2010]
  No changes.

Version 1.4.1beta01 [January 8, 2010]
  Updated CMakeLists.txt for consistent indentation and to avoid an
    unclosed if-statement warning (Philip Lowman).
  Revised Makefile.am and Makefile.in to remove references to Y2KINFO,
    KNOWNBUG, and libpng.la (Robert Schwebel).
  Revised the makefiles to install the same files and symbolic
    links as configure, except for libpng.la and libpng14.la.
  Make png_set|get_compression_buffer_size() available even when
    PNG_WRITE_SUPPORTED is not enabled.
  Revised Makefile.am and Makefile.in to simplify their maintenance.
  Revised scripts/makefile.linux to install a link to libpng14.so.14.1

Version 1.4.1beta02 [January 9, 2010]
  Revised the rest of the makefiles to install a link to libpng14.so.14.1

Version 1.4.1beta03 [January 10, 2010]
  Removed png_set_premultiply_alpha() from scripts/*.def

Version 1.4.1rc01 [January 16, 2010]
  No changes.

Version 1.4.1beta04 [January 23, 2010]
  Revised png_decompress_chunk() to improve speed and memory usage when
    decoding large chunks.
  Added png_set|get_chunk_malloc_max() functions.

Version 1.4.1beta05 [January 26, 2010]
  Relocated "int k" declaration in pngtest.c to minimize its scope.

Version 1.4.1beta06 [January 28, 2010]
  Revised png_decompress_chunk() to use a two-pass method suggested by
    John Bowler.

Version 1.4.1beta07 [February 6, 2010]
  Folded some long lines in the source files.
  Added defineable PNG_USER_CHUNK_CACHE_MAX, PNG_USER_CHUNK_MALLOC_MAX,
    and a PNG_USER_LIMITS_SUPPORTED flag.
  Eliminated use of png_ptr->irowbytes and reused the slot in png_ptr as
    png_ptr->png_user_chunk_malloc_max.
  Revised png_push_save_buffer() to do fewer but larger png_malloc() calls.

Version 1.4.1beta08 [February 6, 2010]
  Minor cleanup and updating of dates and copyright year.

Version 1.5.0beta01 [February 7, 2010]
  Moved declaration of png_struct into private pngstruct.h and png_info
    into pnginfo.h

Version 1.4.1beta09 and 1.5.0beta02 [February 7, 2010]
  Reverted to original png_push_save_buffer() code.

Version 1.4.1beta10 and 1.5.0beta03 [February 8, 2010]
  Return allocated "old_buffer" in png_push_save_buffer() before
    calling png_error(), to avoid a potential memory leak.
  Updated configure script to use SO number 15.

Version 1.5.0beta04 [February 9, 2010]
  Removed malformed "incomplete struct declaration" of png_info from png.h

Version 1.5.0beta05 [February 12, 2010]
  Removed PNG_DEPSTRUCT markup in pngstruct.h and pnginfo.h, and undid the
    linewrapping that it entailed.
  Revised comments in pngstruct.h and pnginfo.h and added pointers to
    the libpng license.
  Changed PNG_INTERNAL to PNG_EXPOSE_INTERNAL_STRUCTURES
  Removed the cbuilder5 project, which has not been updated to 1.4.0.

Version 1.4.1beta12 and 1.5.0beta06 [February 14, 2010]
  Fixed type declaration of png_get_chunk_malloc_max() in pngget.c (Daisuke
    Nishikawa)

Version 1.5.0beta07 [omitted]

Version 1.5.0beta08 [February 19, 2010]
  Changed #ifdef PNG_NO_STDIO_SUPPORTED to #ifdef PNG_NO_CONSOLE_IO_SUPPORTED
    wherever png_snprintf() is used to construct error and warning messages.
  Noted in scripts/makefile.mingw that it expects to be run under MSYS.
  Removed obsolete unused MMX-querying support from contrib/gregbook
  Added exported png_longjmp() function.
  Removed the AIX redefinition of jmpbuf in png.h
  Added -D_ALLSOURCE in configure.ac, makefile.aix, and CMakeLists.txt
    when building on AIX.

Version 1.5.0beta09 [February 19, 2010]
  Removed -D_ALLSOURCE from configure.ac, makefile.aix, and CMakeLists.txt.
  Changed the name of png_ptr->jmpbuf to png_ptr->png_jmpbuf in pngstruct.h

Version 1.5.0beta10 [February 25, 2010]
  Removed unused gzio.c from contrib/pngminim gather and makefile scripts
  Removed replacement error handlers from contrib/gregbook.  Because of
    the new png_longjmp() function they are no longer needed.

Version 1.5.0beta11 [March 6, 2010]
  Removed checking for already-included setjmp.h from pngconf.h
  Fixed inconsistent indentations and made numerous cosmetic changes.
  Revised the "SEE ALSO" style of libpng.3, libpngpf.3, and png.5

Version 1.5.0beta12 [March 9, 2010]
  Moved "#include png.h" inside pngpriv.h and removed "#include png.h" from
    the source files, along with "#define PNG_EXPOSE_INTERNAL_STRUCTURES"
    and "#define PNG_NO_PEDANTIC_WARNINGS" (John Bowler).
  Created new pngdebug.h and moved debug definitions there.

Version 1.5.0beta13 [March 10, 2010]
  Protect pngstruct.h, pnginfo.h, and pngdebug.h from being included twice.
  Revise the "#ifdef" blocks in png_inflate() so it will compile when neither
    PNG_USER_CHUNK_MALLOC_MAX nor PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
    is defined.
  Removed unused png_measure_compressed_chunk() from pngpriv.h and libpngpf.3
  Moved the 'config.h' support from pngconf.h to pngpriv.h
  Removed PNGAPI from the png_longjmp_ptr typedef.
  Eliminated dependence of pngtest.c on the private pngdebug.h file.
  Make all png_debug macros into *unterminated* statements or
    expressions (i.e. a trailing ';' must always be added) and correct
    the format statements in various png_debug messages.

Version 1.5.0beta14 [March 14, 2010]
  Removed direct access to png_ptr->io_ptr from the Windows code in pngtest.c
  Revised Makefile.am to account for recent additions and replacements.
  Corrected CE and OS/2 DEF files (scripts/png*def) for symbols removed and
    added ordinal numbers to the Windows DEF file and corrected the duplicated
    ordinal numbers on CE symbols that are commented out.
  Added back in export symbols that can be present in the Windows build but
    are disabled by default.
  PNG_EXPORT changed to include an 'ordinal' field for DEF file generation.
    PNG_CALLBACK added to make callback definitions uniform.  PNGAPI split
    into PNGCAPI (base C form), PNGAPI (exports) and PNGCBAPI (callbacks),
    and appropriate changes made to all files.  Cygwin builds re-hinged to
    allow procedure call standard changes and to remove the need for the DEF
    file (fixes build on Cygwin).
  Enabled 'attribute' warnings that are relevant to library APIs and callbacks.
  Changed rules for generation of the various symbol files and added a new
    rule for a DEF file (which is also added to the distribution).
  Updated the symbol file generation to stop it adding spurious spaces
    to EOL (coming from preprocessor macro expansion).  Added a facility
    to join tokens in the output and rewrite *.dfn to use this.
  Eliminated scripts/*.def in favor of libpng.def; updated projects/visualc71
    and removed scripts/makefile.cygwin.
  Made PNG_BUILD_DLL safe: it can be set whenever a DLL is being built.
  Removed the include of sys/types.h - apparently unnecessary now on the
    platforms on which it happened (all but Mac OS and RISC OS).
  Moved the Mac OS test into pngpriv.h (the only place it is used.)

Version 1.5.0beta15 [March 17, 2010]
  Added symbols.chk target to Makefile.am to validate the symbols in png.h
    against the new DEF file scripts/symbols.def.
  Changed the default DEF file back to pngwin.def.
  Removed makefile.mingw.
  Eliminated PNG_NO_EXTERN and PNG_ALL_EXTERN

Version 1.5.0beta16 [April 1, 2010]
  Make png_text_struct independent of PNG_iTXt_SUPPORTED, so that
    fields are initialized in all configurations.  The READ/WRITE
    macros (PNG_(READ|WRITE)_iTXt_SUPPORTED) still function as
    before to disable code to actually read or write iTXt chunks
    and iTXt_SUPPORTED can be used to detect presence of either
    read or write support (but it is probably better to check for
    the one actually required - read or write.)
  Combined multiple png_warning() calls for a single error.
  Restored the macro definition of png_check_sig().

Version 1.5.0beta17 [April 17, 2010]
  Added some "(long)" typecasts to printf calls in png_handle_cHRM().
  Documented the fact that png_set_dither() was disabled since libpng-1.4.0.
  Reenabled png_set_dither() but renamed it to png_set_quantize() to reflect
    more accurately what it actually does.  At the same time, renamed
    the PNG_DITHER_[RED,GREEN_BLUE]_BITS macros to
    PNG_QUANTIZE_[RED,GREEN,BLUE]_BITS.
  Added some "(long)" typecasts to printf calls in png_handle_cHRM().
  Freeze build-time only configuration in the build.
    In all prior versions of libpng most configuration options
    controlled by compiler #defines had to be repeated by the
    application code that used libpng.  This patch changes this
    so that compilation options that can only be changed at build
    time are frozen in the build.  Options that are compiler
    dependent (and those that are system dependent) are evaluated
    each time - pngconf.h holds these.  Options that can be changed
    per-file in the application are in png.h.  Frozen options are
    in the new installed header file pnglibconf.h (John Bowler)
  Removed the xcode project because it has not been updated to work
    with libpng-1.5.0.
  Removed the ability to include optional pngusr.h

Version 1.5.0beta18 [April 17, 2010]
  Restored the ability to include optional pngusr.h
  Moved replacements for png_error() and png_warning() from the
    contrib/pngminim project to pngerror.c, for use when warnings or
    errors are disabled via PNG_NO_WARN or PNG_NO_ERROR_TEXT, to avoid
    storing unneeded error/warning text.
  Updated contrib/pngminim project to work with the new pnglibconf.h
  Added some PNG_NO_* defines to contrib/pngminim/*/pngusr.h to save space.

Version 1.5.0beta19 [April 24, 2010]
  Added PNG_{READ,WRITE}_INT_FUNCTIONS_SUPPORTED.  This allows the functions
    to read and write ints to be disabled independently of PNG_USE_READ_MACROS,
    which allows libpng to be built with the functions even though the default
    is to use the macros - this allows applications to choose at app build
    time whether or not to use macros (previously impossible because the
    functions weren't in the default build.)
  Changed Windows calling convention back to __cdecl for API functions.
    For Windows/x86 platforms only:
      __stdcall is no longer needed for Visual Basic, so libpng-1.5.0 uses
      __cdecl throughout (both API functions and callbacks) on Windows/x86
      platforms.
  Replaced visualc6 and visualc71 projects with new vstudio project
  Relaxed the overly-restrictive permissions of some files.

Version 1.5.0beta20 [April 24, 2010]
  Relaxed more overly-restrictive permissions of some files.

Version 1.5.0beta21 [April 27, 2010]
  Removed some unwanted binary bytes and changed CRLF to NEWLINE in the new
    vstudio project files, and some trivial editing of some files in the
    scripts directory.
  Set PNG_NO_READ_BGR, PNG_NO_IO_STATE, and PNG_NO_TIME_RFC1123 in
    contrib/pngminim/decoder/pngusr.h to make a smaller decoder application.

Version 1.5.0beta22 [April 28, 2010]
  Fixed dependencies of GET_INT_32 - it does not require READ_INT_FUNCTIONS
    because it has a macro equivalent.
  Improved the options.awk script; added an "everything off" option.
  Revised contrib/pngminim to use the "everything off" option in pngusr.dfa.

Version 1.5.0beta23 [April 29, 2010]
  Corrected PNG_REMOVED macro to take five arguments.
    The macro was documented with two arguments (name,ordinal), however
    the symbol checking .dfn files assumed five arguments.  The five
    argument form seems more useful so it is changed to that.
  Corrected PNG_UNKNOWN_CHUNKS_SUPPORTED to PNG_HANDLE_AS_UNKNOWN_SUPPORTED
    in gregbook/readpng2.c
  Corrected protection of png_get_user_transform_ptr. The API declaration in
    png.h is removed if both READ and WRITE USER_TRANSFORM are turned off
    but was left defined in pngtrans.c
  Added logunsupported=1 to cause pnglibconf.h to document disabled options.
    This makes the installed pnglibconf.h more readable but causes no
    other change.  The intention is that users of libpng will find it
    easier to understand if an API they need is missing.
  Include png_reset_zstream() in png.c only when PNG_READ_SUPPORTED is defined.
  Removed dummy_inflate.c from contrib/pngminim/encoder
  Removed contrib/pngminim/*/gather.sh; gathering is now done in the makefile.

Version 1.5.0beta24 [May 7, 2010]
  Use bitwise "&" instead of arithmetic mod in pngrutil.c calculation of the
    offset of the png_ptr->rowbuf pointer into png_ptr->big_row_buf.
  Added more blank lines for readability.

Version 1.5.0beta25 [June 18, 2010]
  In pngpread.c: png_push_have_row() add check for new_row > height
  Removed the now-redundant check for out-of-bounds new_row from example.c

Version 1.5.0beta26 [June 18, 2010]
  In pngpread.c: png_push_process_row() add check for too many rows.

Version 1.5.0beta27 [June 18, 2010]
  Removed the check added in beta25 as it is now redundant.

Version 1.5.0beta28 [June 20, 2010]
  Rewrote png_process_IDAT_data to consistently treat extra data as warnings
    and handle end conditions more cleanly.
  Removed the new (beta26) check in png_push_process_row().

Version 1.5.0beta29 [June 21, 2010]
  Revised scripts/options.awk to work on Sunos (but still doesn't work)
  Added comment to options.awk and contrib/pngminim/*/makefile to try nawk.

Version 1.5.0beta30 [June 22, 2010]
  Stop memory leak when reading a malformed sCAL chunk.

Version 1.5.0beta31 [June 26, 2010]
  Revised pngpread.c patch of beta28 to avoid an endless loop.
  Removed some trailing blanks.

Version 1.5.0beta32 [June 26, 2010]
  Removed leftover scripts/options.patch and scripts/options.rej

Version 1.5.0beta33 [July 6, 3010]
  Made FIXED and FLOATING options consistent in the APIs they enable and
    disable.  Corrected scripts/options.awk to handle both command line
    options and options specified in the .dfa files.
  Changed char *msg to PNG_CONST char *msg in pngrutil.c
  Make png_set_sRGB_gAMA_and_cHRM set values using either the fixed or
    floating point APIs, but not both.
  Reversed patch to remove error handler when the jmp_buf is stored in the
    main program structure, not the png_struct.
    The error handler is needed because the default handler in libpng will
    always use the jmp_buf in the library control structure; this is never
    set.  The gregbook code is a useful example because, even though it
    uses setjmp/longjmp, it shows how error handling can be implemented
    using control mechanisms not directly supported by libpng.  The
    technique will work correctly with mechanisms such as Microsoft
    Structure Exceptions or C++ exceptions (compiler willing - note that gcc
    does not by default support interworking of C and C++ error handling.)
  Reverted changes to call png_longjmp in contrib/gregbook where it is not
    appropriate.  If mainprog->jmpbuf is used by setjmp, then png_longjmp
    cannot be used.
  Changed "extern PNG_EXPORT" to "PNG_EXPORT" in png.h (Jan Nijtmans)
  Changed "extern" to "PNG_EXTERN" in pngpriv.h (except for the 'extern "C" {')

Version 1.5.0beta34 [July 12, 2010]
  Put #ifndef PNG_EXTERN, #endif around the define PNG_EXTERN in pngpriv.h

Version 1.5.0beta35 [July 24, 2010]
  Removed some newly-added TAB characters.
  Added -DNO_PNG_SNPRINTF to CFLAGS in scripts/makefile.dj2
  Moved the definition of png_snprintf() outside of the enclosing
    #ifdef blocks in pngconf.h

Version 1.5.0beta36 [July 29, 2010]
  Patches by John Bowler:
  Fixed point APIs are now supported throughout (no missing APIs).
  Internal fixed point arithmetic support exists for all internal floating
    point operations.
  sCAL validates the floating point strings it is passed.
  Safe, albeit rudimentary, Watcom support is provided by PNG_API_RULE==2
  Two new APIs exist to get the number of passes without turning on the
    PNG_INTERLACE transform and to get the number of rows in the current
    pass.
  A new test program, pngvalid.c, validates the gamma code.
  Errors in the 16-bit gamma correction (overflows) have been corrected.
  cHRM chunk testing is done consistently (previously the floating point
    API bypassed it, because the test really didn't work on FP, now the test
    is performed on the actual values to be stored in the PNG file so it
    works in the FP case too.)
  Most floating point APIs now simply call the fixed point APIs after
    converting the values to the fixed point form used in the PNG file.
  The standard headers no longer include zlib.h, which is currently only
    required for pngstruct.h and can therefore be internal.
  Revised png_get_int_32 to undo the PNG two's complement representation of
    negative numbers.

Version 1.5.0beta37 [July 30, 2010]
  Added a typecast in png_get_int_32() in png.h and pngrutil.h to avoid
    a compiler warning.
  Replaced oFFs 0,0 with oFFs -10,20 in pngtest.png

Version 1.5.0beta38 [July 31, 2010]
  Implemented remaining "_fixed" functions.
  Corrected a number of recently introduced warnings mostly resulting from
    safe but uncast assignments to shorter integers.  Also added a zlib
    VStudio release library project because the latest zlib Official Windows
    build does not include such a thing.
  Revised png_get_int_16() to be similar to png_get_int_32().
  Restored projects/visualc71.

Version 1.5.0beta39 [August 2, 2010]
  VisualC/GCC warning fixes, VisualC build fixes
  The changes include support for function attributes in VC in addition to
    those already present in GCC - necessary because without these some
    warnings are unavoidable.  Fixes include signed/unsigned fixes in
    pngvalid and checks with gcc -Wall -Wextra -Wunused.
  VC requires function attributes on function definitions as well as
    declarations, PNG_FUNCTION has been added to enable this and the
    relevant function definitions changed.

Version 1.5.0beta40 [August 6, 2010]
  Correct use of _WINDOWS_ in pngconf.h
  Removed png_mem_ #defines; they are no longer used.
  Added the sRGB chunk to pngtest.png

Version 1.5.0beta41 [August 11, 2010]
  Added the cHRM chunk to pngtest.png
  Don't try to use version-script with cygwin/mingw.
  Revised contrib/gregbook to work under cygwin/mingw.

Version 1.5.0beta42 [August 18, 2010]
  Add .dll.a to the list of extensions to be symlinked by Makefile.am (Yaakov)
  Made all API functions that have const arguments and constant string
    literal pointers declare them (John Bowler).

Version 1.5.0beta43 [August 20, 2010]
  Removed spurious tabs, shorten long lines (no source change)
    Also added scripts/chkfmt to validate the format of all the files that can
    reasonably be validated (it is suggested to run "make distclean" before
    checking, because some machine generated files have long lines.)
  Reformatted the CHANGES file to be more consistent throughout.
  Made changes to address various issues identified by GCC, mostly
    signed/unsigned and shortening problems on assignment but also a few
    difficult to optimize (for GCC) loops.
  Fixed non-GCC fixed point builds.  In png.c a declaration was misplaced
    in an earlier update.  Fixed to declare the auto variables at the head.
  Use cexcept.h in pngvalid.c.

Version 1.5.0beta44 [August 24, 2010]
  Updated CMakeLists.txt to use CMAKE_INSTALL_LIBDIR variable; useful for
    installing libpng in /usr/lib64 (Funda Wang).
  Revised CMakeLists.txt to put the man pages in share/man/man* not man/man*
  Revised CMakeLists.txt to make symlinks instead of copies when installing.
  Changed PNG_LIB_NAME from pngNN to libpngNN in CMakeLists.txt (Philip Lowman)
  Implemented memory checks within pngvalid
  Reformatted/rearranged pngvalid.c to assist use of progressive reader.
  Check interlaced images in pngvalid
  Clarified pngusr.h comments in pnglibconf.dfa
  Simplified the pngvalid error-handling code now that cexcept.h is in place.
  Implemented progressive reader in pngvalid.c for standard tests
  Implemented progressive read in pngvalid.c gamma tests
  Turn on progressive reader in pngvalid.c by default and tidy code.

Version 1.5.0beta45 [August 26, 2010]
  Added an explicit make step to projects/vstudio for pnglibconf.h
    Also corrected zlib.vcxproj into which Visual Studio had introduced
    what it calls an "authoring error".  The change to make pnglibconf.h
    simply copies the file; in the future it may actually generate the
    file from scripts/pnglibconf.dfa as the other build systems do.
  Changed pngvalid to work when floating point APIs are disabled
  Renamed the prebuilt scripts/pnglibconf.h to scripts/pnglibconf.h.prebuilt
  Supply default values for PNG_USER_PRIVATEBUILD and PNG_USER_DLLFNAME_POSTFIX
    in pngpriv.h in case the user neglected to define them in their pngusr.h

Version 1.5.0beta46 [August 28, 2010]
  Added new private header files to libpng_sources in CMakeLists.txt
  Added PNG_READ_16BIT, PNG_WRITE_16BIT, and PNG_16BIT options.
  Added reference to scripts/pnglibconf.h.prebuilt in the visualc71 project.

Version 1.5.0beta47 [September 11, 2010]
  Fixed a number of problems with 64-bit compilation reported by Visual
    Studio 2010 (John Bowler).

Version 1.5.0beta48 [October 4, 2010]
  Updated CMakeLists.txt (Philip Lowman).
  Revised autogen.sh to recognize and use $AUTOCONF, $AUTOMAKE, $AUTOHEADER,
    $AUTOPOINT, $ACLOCAL and $LIBTOOLIZE
  Fixed problem with symbols creation in Makefile.am which was assuming that
    all versions of ccp write to standard output by default (Martin Banky). The
    bug was introduced in libpng-1.2.9beta5.
  Removed unused mkinstalldirs.

Version 1.5.0beta49 [October 8, 2010]
  Undid Makefile.am revision of 1.5.0beta48.

Version 1.5.0beta50 [October 14, 2010]
  Revised Makefile.in to account for mkinstalldirs being removed.
  Added some "(unsigned long)" typecasts in printf statements in pngvalid.c.
  Suppressed a compiler warning in png_handle_sPLT().
  Check for out-of-range text compression mode in png_set_text().

Version 1.5.0beta51 [October 15, 2010]
  Changed embedded dates to "(PENDING RELEASE) in beta releases (and future
    rc releases) to minimize the difference between releases.

Version 1.5.0beta52 [October 16, 2010]
  Restored some of the embedded dates (in png.h, png.c, documentation, etc.)

Version 1.5.0beta53 [October 18, 2010]
  Updated INSTALL to mention using "make maintainer-clean" and to remove
    obsolete statement about a custom ltmain.sh
  Disabled "color-tests" by default in Makefile.am so it will work with
    automake versions earlier than 1.11.1
  Use document name "libpng-manual.txt" instead of "libpng-<version>.txt"
    to simplify version differences.
  Removed obsolete remarks about setjmp handling from INSTALL.
  Revised and renamed the typedef in png.h and png.c that was designed
    to catch library and header mismatch.

Version 1.5.0beta54 [November 10, 2010]
  Require 48 bytes, not 64 bytes, for big_row_buf in overflow checks.
  Used a consistent structure for the pngget.c functions.

Version 1.5.0beta55 [November 21, 2010]
  Revised png_get_uint_32, png_get_int_32, png_get_uint_16 (Cosmin)
  Moved reading of file signature into png_read_sig (Cosmin)
  Fixed atomicity of chunk header serialization (Cosmin)
  Added test for io_state in pngtest.c (Cosmin)
  Added "#!/bin/sh" at the top of contrib/pngminim/*/gather.sh scripts.
  Changes to remove gcc warnings (John Bowler)
    Certain optional gcc warning flags resulted in warnings in libpng code.
    With these changes only -Wconversion and -Wcast-qual cannot be turned on.
    Changes are trivial rearrangements of code.  -Wconversion is not possible
    for pngrutil.c (because of the widespread use of += et al on variables
    smaller than (int) or (unsigned int)) and -Wcast-qual is not possible
    with pngwio.c and pngwutil.c because the 'write' callback and zlib
    compression both fail to declare their input buffers with 'const'.

Version 1.5.0beta56 [December 7, 2010]
  Added the private PNG_UNUSED() macro definition in pngpriv.h.
  Added some commentary about PNG_EXPORT in png.h and pngconf.h
  Revised PNG_EXPORT() macro and added PNG_EXPORTA() macro, with the
    objective of simplifying and improving the cosmetic appearance of png.h.
  Fixed some incorrect "=" macro names in pnglibconf.dfa
  Included documentation of changes in 1.5.0 from 1.4.x in libpng-manual.txt

Version 1.5.0beta57 [December 9, 2010]
  Documented the pngvalid gamma error summary with additional comments and
    print statements.
  Improved missing symbol handling in checksym.awk; symbols missing in both
    the old and new files can now be optionally ignored, treated as errors
    or warnings.
  Removed references to pngvcrd.c and pnggccrd.c from the vstudio project.
  Updated "libpng14" to "libpng15" in the visualc71 project.
  Enabled the strip16 tests in pngvalid.`
  Don't display test results (except PASS/FAIL) when running "make test".
    Instead put them in pngtest-log.txt
  Added "--with-zprefix=<string>" to configure.ac
  Updated the prebuilt configuration files to autoconf version 2.68

Version 1.5.0beta58 [December 19, 2010]
  Fixed interlace image handling and add test cases (John Bowler)
  Fixed the clean rule in Makefile.am to remove pngtest-log.txt
  Made minor changes to work around warnings in gcc 3.4

Version 1.5.0rc01 [December 27, 2010]
  No changes.

Version 1.5.0rc02 [December 27, 2010]
  Eliminated references to the scripts/*.def files in project/visualc71.

Version 1.5.0rc03 [December 28, 2010]
  Eliminated scripts/*.def and revised Makefile.am accordingly

Version 1.5.0rc04 [December 29, 2010]
  Fixed bug in background transformation handling in pngrtran.c (it was
    looking for the flag in png_ptr->transformations instead of in
    png_ptr->flags) (David Raymond).

Version 1.5.0rc05 [December 31, 2010]
  Fixed typo in a comment in CMakeLists.txt (libpng14 => libpng15) (Cosmin)

Version 1.5.0rc06 [January 4, 2011]
  Changed the new configure option "zprefix=string" to "zlib-prefix=string"

Version 1.5.0rc07 [January 4, 2011]
  Updated copyright year.

Version 1.5.0 [January 6, 2011]
  No changes.

version 1.5.1beta01 [January 8, 2011]
  Added description of png_set_crc_action() to the manual.
  Added a note in the manual that the type of the iCCP profile was changed
    from png_charpp to png_bytepp in png_get_iCCP().  This change happened
    in version 1.5.0beta36 but is not noted in the CHANGES.  Similarly,
    it was changed from png_charpp to png_const_bytepp in png_set_iCCP().
  Ensure that png_rgb_to_gray ignores palette mapped images, if libpng
    internally happens to call it with one.
  Fixed a failure to handle palette mapped images correctly.

Version 1.5.1beta02 [January 14, 2011]
  Fixed a bug in handling of interlaced images (bero at arklinux.org).
  Updated CMakeLists.txt (Clifford Yapp)

Version 1.5.1beta03 [January 14, 2011]
  Fixed typecasting of some png_debug() statements (Cosmin)

Version 1.5.1beta04 [January 16, 2011]
  Updated documentation of png_set|get_tRNS() (Thomas Klausner).
  Mentioned in the documentation that applications must #include "zlib.h"
    if they need access to anything in zlib.h, and that a number of
    macros such as png_memset() are no longer accessible by applications.
  Corrected pngvalid gamma test "sample" function to access all of the color
    samples of each pixel, instead of sampling the red channel three times.
  Prefixed variable names index, div, exp, gamma with "png_" to avoid "shadow"
    warnings, and (mistakenly) changed png_exp() to exp().

Version 1.5.1beta05 [January 16, 2011]
  Changed variable names png_index, png_div, png_exp, and png_gamma to
    char_index, divisor, exp_b10, and gamma_val, respectively, and
    changed exp() back to png_exp().

Version 1.5.1beta06 [January 20, 2011]
  Prevent png_push_crc_skip() from hanging while reading an unknown chunk
    or an over-large compressed zTXt chunk with the progressive reader.
  Eliminated more GCC "shadow" warnings.
  Revised png_fixed() in png.c to avoid compiler warning about reaching the
    end without returning anything.

Version 1.5.1beta07 [January 22, 2011]
  In the manual, describe the png_get_IHDR() arguments in the correct order.
  Added const_png_structp and const_png_infop types, and used them in
    prototypes for most png_get_*() functions.

Version 1.5.1beta08 [January 23, 2011]
  Added png_get_io_chunk_type() and deprecated png_get_io_chunk_name()
  Added synopses for the IO_STATE functions and other missing synopses
    to the manual. Removed the synopses from libpngpf.3 because they
    were out of date and no longer useful.  Better information can be
    obtained by reading the prototypes and comments in pngpriv.h
  Attempted to fix cpp on Solaris with S. Studio 12 cc, fix build
    Added a make macro DFNCPP that is a CPP that will accept the tokens in
    a .dfn file and adds configure stuff to test for such a CPP.  ./configure
    should fail if one is not available.
  Corrected const_png_ in png.h to png_const_ to avoid polluting the namespace.
  Added png_get_current_row_number and png_get_current_pass_number for the
    benefit of the user transform callback.
  Added png_process_data_pause and png_process_data_skip for the benefit of
    progressive readers that need to stop data processing or want to optimize
    skipping of unread data (e.g., if the reader marks a chunk to be skipped.)

Version 1.5.1beta09 [January 24, 2011]
  Enhanced pngvalid, corrected an error in gray_to_rgb, corrected doc error.
    pngvalid contains tests of transforms, which tests are currently disabled
    because they are incompletely tested.  gray_to_rgb was failing to expand
    the bit depth for smaller bit depth images; this seems to be a long
    standing error and resulted, apparently, in invalid output
    (CVE-2011-0408, CERT VU#643140).  The documentation did not accurately
    describe what libpng really does when converting RGB to gray.

Version 1.5.1beta10 [January 27, 2010]
  Fixed incorrect examples of callback prototypes in the manual, that were
    introduced in libpng-1.0.0.
  In addition the order of the png_get_uint macros with respect to the
    relevant function definitions has been reversed.  This helps the
    preprocessing of the symbol files be more robust.  Furthermore, the
    symbol file preprocessing now uses -DPNG_NO_USE_READ_MACROS even when
    the library may actually be built with PNG_USE_READ_MACROS; this stops
    the read macros interfering with the symbol file format.
  Made the manual, synopses, and function prototypes use the function
    argument names file_gamma, int_file_gamma, and srgb_intent consistently.

Version 1.5.1beta11 [January 28, 2011]
  Changed PNG_UNUSED from "param=param;" to "{if(param){}}".
  Corrected local variable type in new API png_process_data_skip()
    The type was self-evidently incorrect but only causes problems on 64-bit
    architectures.
  Added transform tests to pngvalid and simplified the arguments.

Version 1.5.1rc01 [January 29, 2011]
  No changes.

Version 1.5.1rc02 [January 31, 2011]
  Added a request in the manual that applications do not use "png_" or
    "PNG_" to begin any of their own symbols.
  Changed PNG_UNUSED to "(void)param;" and updated the commentary in pngpriv.h

Version 1.5.1 [February 3, 2011]
  No changes.

Version 1.5.2beta01 [February 13, 2011]
  More -Wshadow fixes for older gcc compilers.  Older gcc versions apparently
    check formal parameters names in function declarations (as well as
    definitions) to see if they match a name in the global namespace.
  Revised PNG_EXPORTA macro to not use an empty parameter, to accommodate the
    old VisualC++ preprocessor.
  Turned on interlace handling in png_read_png().
  Fixed gcc pendantic warnings.
  Handle longjmp in Cygwin.
  Fixed png_get_current_row_number() in the interlaced case.
  Cleaned up ALPHA flags and transformations.
  Implemented expansion to 16 bits.

Version 1.5.2beta02 [February 19, 2011]
  Fixed mistake in the descriptions of user read_transform and write_transform
    function prototypes in the manual.  The row_info struct is png_row_infop.
  Reverted png_get_current_row_number() to previous (1.5.2beta01) behavior.
  Corrected png_get_current_row_number documentation
  Fixed the read/write row callback documentation.
    This documents the current behavior, where the callback is called after
    every row with information pertaining to the next row.

Version 1.5.2beta03 [March 3, 2011]
  Fixed scripts/makefile.vcwin32
  Updated contrib/pngsuite/README to add the word "modify".
  Define PNG_ALLOCATED to blank when _MSC_VER<1300.

Version 1.5.2rc01 [March 19, 2011]
  Define remaining attributes to blank when MSC_VER<1300.
  ifdef out mask arrays in pngread.c when interlacing is not supported.

Version 1.5.2rc02 [March 22, 2011]
  Added a hint to try CPP=/bin/cpp if "cpp -E" fails in scripts/pnglibconf.mak
    and in contrib/pngminim/*/makefile, eg., on SunOS 5.10, and removed "strip"
    from the makefiles.
  Fixed a bug (present since libpng-1.0.7) that makes png_handle_sPLT() fail
    to compile when PNG_NO_POINTER_INDEXING is defined (Chubanov Kirill)

Version 1.5.2rc03 [March 24, 2011]
  Don't include standard header files in png.h while building the symbol table,
    to avoid cpp failure on SunOS (introduced PNG_BUILDING_SYMBOL_TABLE macro).

Version 1.5.2 [March 31, 2011]
  No changes.

Version 1.5.3beta01 [April 1, 2011]
  Re-initialize the zlib compressor before compressing non-IDAT chunks.
  Added API functions to set parameters for zlib compression of non-IDAT
    chunks.

Version 1.5.3beta02 [April 3, 2011]
  Updated scripts/symbols.def with new API functions.
  Only compile the new zlib re-initializing code when text or iCCP is
    supported, using PNG_WRITE_COMPRESSED_TEXT_SUPPORTED macro.
  Improved the optimization of the zlib CMF byte (see libpng-1.2.6beta03).
  Optimize the zlib CMF byte in non-IDAT compressed chunks

Version 1.5.3beta03 [April 16, 2011]
  Fixed gcc -ansi -pedantic compile. A strict ANSI system does not have
    snprintf, and the "__STRICT_ANSI__" detects that condition more reliably
    than __STDC__ (John Bowler).
  Removed the PNG_PTR_NORETURN attribute because it too dangerous. It tells
    the compiler that a user supplied callback (the error handler) does not
    return, yet there is no guarantee in practice that the application code
    will correctly implement the error handler because the compiler only
    issues a warning if there is a mistake (John Bowler).
  Removed the no-longer-used PNG_DEPSTRUCT macro.
  Updated the zlib version to 1.2.5 in the VStudio project.
  Fixed 64-bit builds where png_uint_32 is smaller than png_size_t in
    pngwutil.c (John Bowler).
  Fixed bug with stripping the filler or alpha channel when writing, that
    was introduced in libpng-1.5.2beta01 (bug report by Andrew Church).

Version 1.5.3beta04 [April 27, 2011]
  Updated pngtest.png with the new zlib CMF optimization.
  Cleaned up conditional compilation code and of background/gamma handling
    Internal changes only except a new option to avoid compiling the
    png_build_grayscale_palette API (which is not used at all internally.)
    The main change is to move the transform tests (READ_TRANSFORMS,
    WRITE_TRANSFORMS) up one level to the caller of the APIs.  This avoids
    calls to spurious functions if all transforms are disabled and slightly
    simplifies those functions.  Pngvalid modified to handle this.
    A minor change is to stop the strip_16 and expand_16 interfaces from
    disabling each other; this allows the future alpha premultiplication
    code to use 16-bit intermediate values while still producing 8-bit output.
    png_do_background and png_do_gamma have been simplified to take a single
    pointer to the png_struct rather than pointers to every item required
    from the png_struct. This makes no practical difference to the internal
    code.
  A serious bug in the pngvalid internal routine 'standard_display_init' has
    been fixed - this failed to initialize the red channel and accidentally
    initialized the alpha channel twice.
  Changed png_struct jmp_buf member name from png_jmpbuf to tmp_jmpbuf to
    avoid a possible clash with the png_jmpbuf macro on some platforms.

Version 1.5.3beta05 [May 6, 2011]
  Added the "_POSIX_SOURCE" feature test macro to ensure libpng sees the
    correct API. _POSIX_SOURCE is defined in pngpriv.h, pngtest.c and
    pngvalid.c to ensure that POSIX conformant systems disable non-POSIX APIs.
  Removed png_snprintf and added formatted warning messages.  This change adds
    internal APIs to allow png_warning messages to have parameters without
    requiring the host OS to implement snprintf.  As a side effect the
    dependency of the tIME-supporting RFC1132 code on stdio is removed and
    PNG_NO_WARNINGS does actually work now.
  Pass "" instead of '\0' to png_default_error() in png_err().  This mistake
    was introduced in libpng-1.2.20beta01.
  Added PNG_WRITE_OPTIMIZE_CMF_SUPPORTED macro to make the zlib "CMF" byte
    optimization configureable.
  IDAT compression failed if preceded by a compressed text chunk (bug
    introduced in libpng-1.5.3beta01-02).  This was because the attempt to
    reset the zlib stream in png_write_IDAT happened after the first IDAT
    chunk had been deflated - much too late.  In this change internal
    functions were added to claim/release the z_stream and, hopefully, make
    the code more robust.  Also deflateEnd checking is added - previously
    libpng would ignore an error at the end of the stream.

Version 1.5.3beta06 [May 8, 2011]
  Removed the -D_ALL_SOURCE from definitions for AIX in CMakeLists.txt
  Implemented premultiplied alpha support: png_set_alpha_mode API

Version 1.5.3beta07 [May 11, 2011]
  Added expand_16 support to the high level interface.
  Added named value and 'flag' gamma support to png_set_gamma.  Made a minor
    change from the previous (unreleased) ABI/API to hide the exact value used
    for Macs - it's not a good idea to embed this in the ABI!
  Moved macro definitions for PNG_HAVE_IHDR, PNG_HAVE_PLTE, and PNG_AFTER_IDAT
    from pngpriv.h to png.h because they must be visible to applications
    that call png_set_unknown_chunks().
  Check for up->location !PNG_AFTER_IDAT when writing unknown chunks
    before IDAT.

Version 1.5.3beta08 [May 16, 2011]
  Improved "pngvalid --speed" to exclude more of pngvalid from the time.
  Documented png_set_alpha_mode(), other changes in libpng.3/libpng-manual.txt
  The cHRM chunk now sets the defaults for png_set_rgb_to_gray() (when negative
    parameters are supplied by the caller), while in the absence of cHRM
    sRGB/Rec 709 values are still used.
  The bKGD chunk no longer overwrites the background value set by
    png_set_background(), allowing the latter to be used before the file
    header is read. It never performed any useful function to override
    the default anyway.
  Added memory overwrite and palette image checks to pngvalid.c
    Previously palette image code was poorly checked. Since the transformation
    code has a special palette path in most cases this was a severe weakness.
  Minor cleanup and some extra checking in pngrutil.c and pngrtran.c. When
    expanding an indexed image, always expand to RGBA if transparency is
    present.

Version 1.5.3beta09 [May 17, 2011]
  Reversed earlier 1.5.3 change of transformation order; move png_expand_16
    back where it was.  The change doesn't work because it requires 16-bit
    gamma tables when the code only generates 8-bit ones.  This fails
    silently; the libpng code just doesn't do any gamma correction.  Moving
    the tests back leaves the old, inaccurate, 8-bit gamma calculations, but
    these are clearly better than none!

Version 1.5.3beta10 [May 20, 2011]

  png_set_background() and png_expand_16() did not work together correctly.
    This problem is present in 1.5.2; if png_set_background is called with
    need_expand false and the matching 16 bit color libpng erroneously just
    treats it as an 8-bit color because of where png_do_expand_16 is in the
    transform list.  This simple fix reduces the supplied colour to 8-bits,
    so it gets smashed, but this is better than the current behavior.
  Added tests for expand16, more fixes for palette image tests to pngvalid.
    Corrects the code for palette image tests and disables attempts to
    validate palette colors.

Version 1.5.3rc01 [June 3, 2011]
  No changes.

Version 1.5.3rc02 [June 8, 2011]
  Fixed uninitialized memory read in png_format_buffer() (Bug report by
    Frank Busse, CVE-2011-2501, related to CVE-2004-0421).

Version 1.5.3beta11 [June 11, 2011]
  Fixed png_handle_sCAL which is broken in 1.5; added sCAL to pngtest.png
  Revised documentation about png_set_user_limits() to say that it also affects
    png writing.
  Revised handling of png_set_user_limits() so that it can increase the
    limit beyond the PNG_USER_WIDTH|HEIGHT_MAX; previously it could only
    reduce it.
  Make the 16-to-8 scaling accurate. Dividing by 256 with no rounding is
    wrong (high by one) 25% of the time. Dividing by 257 with rounding is
    wrong in 128 out of 65536 cases. Getting the right answer all the time
    without division is easy.
  Added "_SUPPORTED" to the PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION macro.
  Added projects/owatcom, an IDE project for OpenWatcom to replace
    scripts/makefile.watcom.  This project works with OpenWatcom 1.9. The
    IDE autogenerates appropriate makefiles (libpng.mk) for batch processing.
    The project is configurable, unlike the Visual Studio project, so long
    as the developer has an awk.
  Changed png_set_gAMA to limit the gamma value range so that the inverse
    of the stored value cannot overflow the fixed point representation,
    and changed other things OpenWatcom warns about.
  Revised pngvalid.c to test PNG_ALPHA_MODE_SUPPORTED correctly. This allows
    pngvalid to build when ALPHA_MODE is not supported, which is required if
    it is to build on libpng 1.4.
  Removed string/memory macros that are no longer used and are not
    necessarily fully supportable, particularly png_strncpy and png_snprintf.
  Added log option to pngvalid.c and attempted to improve gamma messages.
  
Version 1.5.3 [omitted]
  People found the presence of a beta release following an rc release
    to be confusing; therefore we bump the version to libpng-1.5.4beta01
    and there will be no libpng-1.5.3 release.

Version 1.5.4beta01 [June 14, 2011]
  Made it possible to undefine PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
    to get the same (inaccurate) output as libpng-1.5.2 and earlier.
  Moved definitions of PNG_HAVE_IHDR, PNG_AFTER_IDAT, and PNG_HAVE_PLTE
    outside of an unknown-chunk block in png.h because they are also
    needed for other uses.

Version 1.5.4beta02 [June 14, 2011]
  Fixed and clarified LEGACY 16-to-8 scaling code.
  Added png_set_chop_16() API, to match inaccurate results from previous
    libpng versions.
  Removed the ACCURATE and LEGACY options (they are no longer useable)
  Use the old scaling method for background if png_set_chop_16() was
    called.
  Made png_set_chop_16() API removeable by disabling PNG_CHOP_16_TO_8_SUPPORTED

Version 1.5.4beta03 [June 15, 2011]
  Fixed a problem in png_do_expand_palette() exposed by optimization in
    1.5.3beta06
  Also removed a spurious and confusing "trans" member ("trans") from png_info.
  The palette expand optimization prevented expansion to an intermediate RGBA
    form if tRNS was present but alpha was marked to be stripped; this exposed
    a check for tRNS in png_do_expand_palette() which is inconsistent with the
    code elsewhere in libpng.
  Correction to the expand_16 code; removed extra instance of
    png_set_scale_16_to_8 from pngpriv.h

Version 1.5.4beta04 [June 16, 2011]
  Added a missing "#ifdef PNG_READ_BACKGROUND_SUPPORTED/#endif" in pngrtran.c
  Added PNG_TRANSFORM_CHOP_16 to the high-level read transforms.
  Made PNG_READ_16_TO_8_ACCURATE_SCALE configurable again.  If this is
    not enabled, png_set_strip_16() and png_do_scale_16_to_8() aren't built.
  Revised contrib/visupng, gregbook, and pngminim to demonstrate chop_16_to_8

Version 1.5.4beta05 [June 16, 2011]
  Renamed png_set_strip_16() to png_set_scale_16() and renamed
    png_set_chop_16() to png_set_strip(16) in an attempt to minimize the
    behavior changes between libpng14 and libpng15.

Version 1.5.4beta06 [June 18, 2011]
  Fixed new bug that was causing both strip_16 and scale_16 to be applied.

Version 1.5.4beta07 [June 19, 2011]
  Fixed pngvalid, simplified macros, added checking for 0 in sCAL.
    The ACCURATE scale macro is no longer defined in 1.5 - call the
    png_scale_16_to_8 API.  Made sure that PNG_READ_16_TO_8 is still defined
    if the png_strip_16_to_8 API is present.  png_check_fp_number now
    maintains some state so that positive, negative and zero values are
    identified.  sCAL uses these to be strictly spec conformant.

Version 1.5.4beta08 [June 23, 2011]
  Fixed pngvalid if ACCURATE_SCALE is defined.
  Updated scripts/pnglibconf.h.prebuilt.

Version 1.5.4rc01 [June 30, 2011]
  Define PNG_ALLOCATED to "restrict" only if MSC_VER >= 1400.

Version 1.5.4 [July 7, 2011]

Send comments/corrections/commendations to png-mng-implement at lists.sf.net
(subscription required; visit
https://lists.sourceforge.net/lists/listinfo/png-mng-implement
to subscribe)
or to glennrp at users.sourceforge.net

Glenn R-P
*/ }
#endif