Issue #12016: Multibyte CJK decoders now resynchronize faster

They only ignore the first byte of an invalid byte sequence.

For example, b'\xff\n'.decode('gb2312', 'replace') gives '\ufffd\n' instead of
'\ufffd'.

5 files changed, 36 insertions, 36 deletions

diff --git a/Modules/cjkcodecs/_codecs_cn.c b/Modules/cjkcodecs/_codecs_cn.c
index ab4e659..9e9e96c 100644
--- a/Modules/cjkcodecs/_codecs_cn.c
+++ b/Modules/cjkcodecs/_codecs_cn.c
@@ -85,7 +85,7 @@ DECODER(gb2312)
         TRYMAP_DEC(gb2312, **outbuf, c ^ 0x80, IN2 ^ 0x80) {
             NEXT(2, 1)
         }
-        else return 2;
+        else return 1;
     }
 
     return 0;
@@ -141,7 +141,7 @@ DECODER(gbk)
         REQUIRE_INBUF(2)
 
         GBK_DECODE(c, IN2, **outbuf)
-        else return 2;
+        else return 1;
 
         NEXT(2, 1)
     }
@@ -267,7 +267,7 @@ DECODER(gb18030)
             c3 = IN3;
             c4 = IN4;
             if (c < 0x81 || c3 < 0x81 || c4 < 0x30 || c4 > 0x39)
-                return 4;
+                return 1;
             c -= 0x81;  c2 -= 0x30;
             c3 -= 0x81; c4 -= 0x30;
 
@@ -292,12 +292,12 @@ DECODER(gb18030)
                     continue;
                 }
             }
-            return 4;
+            return 1;
         }
 
         GBK_DECODE(c, c2, **outbuf)
         else TRYMAP_DEC(gb18030ext, **outbuf, c, c2);
-        else return 2;
+        else return 1;
 
         NEXT(2, 1)
     }
@@ -400,7 +400,7 @@ DECODER(hz)
             else if (c2 == '\n')
                 ; /* line-continuation */
             else
-                return 2;
+                return 1;
             NEXT(2, 0);
             continue;
         }
@@ -419,7 +419,7 @@ DECODER(hz)
                 NEXT(2, 1)
             }
             else
-                return 2;
+                return 1;
         }
     }
 
diff --git a/Modules/cjkcodecs/_codecs_hk.c b/Modules/cjkcodecs/_codecs_hk.c
index 558a42f..d3ad04b 100644
--- a/Modules/cjkcodecs/_codecs_hk.c
+++ b/Modules/cjkcodecs/_codecs_hk.c
@@ -161,7 +161,7 @@ DECODER(big5hkscs)
         case 0x8864: WRITE2(0x00ca, 0x030c); break;
         case 0x88a3: WRITE2(0x00ea, 0x0304); break;
         case 0x88a5: WRITE2(0x00ea, 0x030c); break;
-        default: return 2;
+        default: return 1;
         }
 
         NEXT(2, 2) /* all decoded codepoints are pairs, above. */
diff --git a/Modules/cjkcodecs/_codecs_jp.c b/Modules/cjkcodecs/_codecs_jp.c
index a05e01b..a500696 100644
--- a/Modules/cjkcodecs/_codecs_jp.c
+++ b/Modules/cjkcodecs/_codecs_jp.c
@@ -112,7 +112,7 @@ DECODER(cp932)
         TRYMAP_DEC(cp932ext, **outbuf, c, c2);
         else if ((c >= 0x81 && c <= 0x9f) || (c >= 0xe0 && c <= 0xea)){
             if (c2 < 0x40 || (c2 > 0x7e && c2 < 0x80) || c2 > 0xfc)
-                return 2;
+                return 1;
 
             c = (c < 0xe0 ? c - 0x81 : c - 0xc1);
             c2 = (c2 < 0x80 ? c2 - 0x40 : c2 - 0x41);
@@ -120,7 +120,7 @@ DECODER(cp932)
             c2 = (c2 < 0x5e ? c2 : c2 - 0x5e) + 0x21;
 
             TRYMAP_DEC(jisx0208, **outbuf, c, c2);
-            else return 2;
+            else return 1;
         }
         else if (c >= 0xf0 && c <= 0xf9) {
             if ((c2 >= 0x40 && c2 <= 0x7e) ||
@@ -128,10 +128,10 @@ DECODER(cp932)
                 OUT1(0xe000 + 188 * (c - 0xf0) +
                      (c2 < 0x80 ? c2 - 0x40 : c2 - 0x41))
             else
-                return 2;
+                return 1;
         }
         else
-            return 2;
+            return 1;
 
         NEXT(2, 1)
     }
@@ -256,7 +256,7 @@ DECODER(euc_jis_2004)
                 NEXT(2, 1)
             }
             else
-                return 2;
+                return 1;
         }
         else if (c == 0x8f) {
             unsigned char c2, c3;
@@ -274,7 +274,7 @@ DECODER(euc_jis_2004)
                 continue;
             }
             else TRYMAP_DEC(jisx0212, **outbuf, c2, c3) ;
-            else return 3;
+            else return 1;
             NEXT(3, 1)
         }
         else {
@@ -300,7 +300,7 @@ DECODER(euc_jis_2004)
                 NEXT(2, 2)
                 continue;
             }
-            else return 2;
+            else return 1;
             NEXT(2, 1)
         }
     }
@@ -388,7 +388,7 @@ DECODER(euc_jp)
                 NEXT(2, 1)
             }
             else
-                return 2;
+                return 1;
         }
         else if (c == 0x8f) {
             unsigned char c2, c3;
@@ -401,7 +401,7 @@ DECODER(euc_jp)
                 NEXT(3, 1)
             }
             else
-                return 3;
+                return 1;
         }
         else {
             unsigned char c2;
@@ -417,7 +417,7 @@ DECODER(euc_jp)
 #endif
                 TRYMAP_DEC(jisx0208, **outbuf,
                            c ^ 0x80, c2 ^ 0x80) ;
-            else return 2;
+            else return 1;
             NEXT(2, 1)
         }
     }
@@ -502,7 +502,7 @@ DECODER(shift_jis)
             REQUIRE_INBUF(2)
             c2 = IN2;
             if (c2 < 0x40 || (c2 > 0x7e && c2 < 0x80) || c2 > 0xfc)
-                return 2;
+                return 1;
 
             c1 = (c < 0xe0 ? c - 0x81 : c - 0xc1);
             c2 = (c2 < 0x80 ? c2 - 0x40 : c2 - 0x41);
@@ -522,10 +522,10 @@ DECODER(shift_jis)
                 continue;
             }
             else
-                return 2;
+                return 1;
         }
         else
-            return 2;
+            return 1;
 
         NEXT(1, 1) /* JIS X 0201 */
     }
@@ -645,7 +645,7 @@ DECODER(shift_jis_2004)
             REQUIRE_INBUF(2)
             c2 = IN2;
             if (c2 < 0x40 || (c2 > 0x7e && c2 < 0x80) || c2 > 0xfc)
-                return 2;
+                return 1;
 
             c1 = (c < 0xe0 ? c - 0x81 : c - 0xc1);
             c2 = (c2 < 0x80 ? c2 - 0x40 : c2 - 0x41);
@@ -671,7 +671,7 @@ DECODER(shift_jis_2004)
                     NEXT_OUT(2)
                 }
                 else
-                    return 2;
+                    return 1;
                 NEXT_IN(2)
             }
             else { /* Plane 2 */
@@ -689,13 +689,13 @@ DECODER(shift_jis_2004)
                     continue;
                 }
                 else
-                    return 2;
+                    return 1;
                 NEXT(2, 1)
             }
             continue;
         }
         else
-            return 2;
+            return 1;
 
         NEXT(1, 1) /* JIS X 0201 */
     }
diff --git a/Modules/cjkcodecs/_codecs_kr.c b/Modules/cjkcodecs/_codecs_kr.c
index 9272e36..f5697dd 100644
--- a/Modules/cjkcodecs/_codecs_kr.c
+++ b/Modules/cjkcodecs/_codecs_kr.c
@@ -123,7 +123,7 @@ DECODER(euc_kr)
             if ((*inbuf)[2] != EUCKR_JAMO_FIRSTBYTE ||
                 (*inbuf)[4] != EUCKR_JAMO_FIRSTBYTE ||
                 (*inbuf)[6] != EUCKR_JAMO_FIRSTBYTE)
-                return 8;
+                return 1;
 
             c = (*inbuf)[3];
             if (0xa1 <= c && c <= 0xbe)
@@ -143,7 +143,7 @@ DECODER(euc_kr)
                 jong = NONE;
 
             if (cho == NONE || jung == NONE || jong == NONE)
-                return 8;
+                return 1;
 
             OUT1(0xac00 + cho*588 + jung*28 + jong);
             NEXT(8, 1)
@@ -152,7 +152,7 @@ DECODER(euc_kr)
             NEXT(2, 1)
         }
         else
-            return 2;
+            return 1;
     }
 
     return 0;
@@ -208,7 +208,7 @@ DECODER(cp949)
         REQUIRE_INBUF(2)
         TRYMAP_DEC(ksx1001, **outbuf, c ^ 0x80, IN2 ^ 0x80);
         else TRYMAP_DEC(cp949ext, **outbuf, c, IN2);
-        else return 2;
+        else return 1;
 
         NEXT(2, 1)
     }
@@ -375,7 +375,7 @@ DECODER(johab)
             i_jong = johabidx_jongseong[c_jong];
 
             if (i_cho == NONE || i_jung == NONE || i_jong == NONE)
-                return 2;
+                return 1;
 
             /* we don't use U+1100 hangul jamo yet. */
             if (i_cho == FILL) {
@@ -391,7 +391,7 @@ DECODER(johab)
                         OUT1(0x3100 |
                           johabjamo_jungseong[c_jung])
                     else
-                        return 2;
+                        return 1;
                 }
             } else {
                 if (i_jung == FILL) {
@@ -399,7 +399,7 @@ DECODER(johab)
                         OUT1(0x3100 |
                           johabjamo_choseong[c_cho])
                     else
-                        return 2;
+                        return 1;
                 }
                 else
                     OUT1(0xac00 +
@@ -414,7 +414,7 @@ DECODER(johab)
                 c2 < 0x31 || (c2 >= 0x80 && c2 < 0x91) ||
                 (c2 & 0x7f) == 0x7f ||
                 (c == 0xda && (c2 >= 0xa1 && c2 <= 0xd3)))
-                return 2;
+                return 1;
             else {
                 unsigned char t1, t2;
 
@@ -425,7 +425,7 @@ DECODER(johab)
                 t2 = (t2 < 0x5e ? t2 : t2 - 0x5e) + 0x21;
 
                 TRYMAP_DEC(ksx1001, **outbuf, t1, t2);
-                else return 2;
+                else return 1;
                 NEXT(2, 1)
             }
         }
diff --git a/Modules/cjkcodecs/_codecs_tw.c b/Modules/cjkcodecs/_codecs_tw.c
index 38cf723..916298d 100644
--- a/Modules/cjkcodecs/_codecs_tw.c
+++ b/Modules/cjkcodecs/_codecs_tw.c
@@ -55,7 +55,7 @@ DECODER(big5)
         TRYMAP_DEC(big5, **outbuf, c, IN2) {
             NEXT(2, 1)
         }
-        else return 2;
+        else return 1;
     }
 
     return 0;
@@ -109,7 +109,7 @@ DECODER(cp950)
 
         TRYMAP_DEC(cp950ext, **outbuf, c, IN2);
         else TRYMAP_DEC(big5, **outbuf, c, IN2);
-        else return 2;
+        else return 1;
 
         NEXT(2, 1)
     }