[svn-r14738] Description:

	Bring r14737 back from the 1.8 branch:    Fix bug which would
incorrectly encode the member offsets for compound datatypes whose size was
between 256 & 511 bytes, when the "use the latest format" feature was enabled.

Tested on:
   Mac OS X/32 10.5.2 (amazon) w/debug
   FreeBSD/32 6.2 (duty) w/production

6 files changed, 44 insertions, 11 deletions

diff --git a/src/H5B2int.c b/src/H5B2int.c
index 2625c63..eae1291 100644
--- a/src/H5B2int.c
+++ b/src/H5B2int.c
@@ -203,7 +203,7 @@ HDmemset(shared->page, 0, shared->node_size);
 
     /* Compute size to store # of records in each node */
     /* (uses leaf # of records because its the largest) */
-    shared->max_nrec_size = (H5V_log2_gen((uint64_t)shared->node_info[0].max_nrec) + 7) / 8;
+    shared->max_nrec_size = H5V_limit_enc_size((uint64_t)shared->node_info[0].max_nrec);
     HDassert(shared->max_nrec_size <= H5B2_SIZEOF_RECORDS_PER_NODE);
 
     /* Initialize internal node info */
@@ -217,7 +217,7 @@ HDmemset(shared->page, 0, shared->node_size);
 
             shared->node_info[u].cum_max_nrec = ((shared->node_info[u].max_nrec + 1) * 
                 shared->node_info[u - 1].cum_max_nrec) + shared->node_info[u].max_nrec;
-            shared->node_info[u].cum_max_nrec_size = (H5V_log2_gen((uint64_t)shared->node_info[u].cum_max_nrec) + 7) / 8;
+            shared->node_info[u].cum_max_nrec_size = H5V_limit_enc_size((uint64_t)shared->node_info[u].cum_max_nrec);
 
             if((shared->node_info[u].nat_rec_fac = H5FL_fac_init(shared->type->nrec_size * shared->node_info[u].max_nrec)) == NULL)
                 HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't create node native key block factory")
@@ -576,7 +576,7 @@ H5B2_split_root(H5F_t *f, hid_t dxpl_id, H5B2_t *bt2, unsigned *bt2_flags_ptr)
     shared->node_info[shared->depth].merge_nrec = (shared->node_info[shared->depth].max_nrec * shared->merge_percent) / 100;
     shared->node_info[shared->depth].cum_max_nrec = ((shared->node_info[shared->depth].max_nrec + 1) * 
         shared->node_info[shared->depth - 1].cum_max_nrec) + shared->node_info[shared->depth].max_nrec;
-    shared->node_info[shared->depth].cum_max_nrec_size = (H5V_log2_gen((uint64_t)shared->node_info[shared->depth].cum_max_nrec) + 7) / 8;
+    shared->node_info[shared->depth].cum_max_nrec_size = H5V_limit_enc_size((uint64_t)shared->node_info[shared->depth].cum_max_nrec);
     if((shared->node_info[shared->depth].nat_rec_fac = H5FL_fac_init(shared->type->nrec_size * shared->node_info[shared->depth].max_nrec)) == NULL)
 	HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't create node native key block factory")
     if((shared->node_info[shared->depth].node_ptr_fac = H5FL_fac_init(sizeof(H5B2_node_ptr_t) * (shared->node_info[shared->depth].max_nrec + 1))) == NULL)
diff --git a/src/H5FScache.c b/src/H5FScache.c
index 74a9aab..8ad9631 100644
--- a/src/H5FScache.c
+++ b/src/H5FScache.c
@@ -606,7 +606,7 @@ HDfprintf(stderr, "%s: fspace->addr = %a, fs_addr = %a\n", FUNC, fspace->addr, f
         unsigned sect_cnt_size;         /* The size of the section size counts */
 
         /* Compute the size of the section counts */
-        sect_cnt_size = MAX(1, (H5V_log2_gen(fspace->serial_sect_count) + 7) / 8);
+        sect_cnt_size = H5V_limit_enc_size((uint64_t)fspace->serial_sect_count);
 #ifdef QAK
 HDfprintf(stderr, "%s: sect_cnt_size = %u\n", FUNC, sect_cnt_size);
 HDfprintf(stderr, "%s: fspace->sect_len_size = %u\n", FUNC, fspace->sect_len_size);
@@ -905,7 +905,7 @@ HDfprintf(stderr, "%s: sinfo->fspace->addr = %a\n", FUNC, sinfo->fspace->addr);
         /* Set up user data for iterator */
         udata.sinfo = sinfo;
         udata.p = &p;
-        udata.sect_cnt_size = MAX(1, (H5V_log2_gen(sinfo->fspace->serial_sect_count) + 7) / 8);
+        udata.sect_cnt_size = H5V_limit_enc_size((uint64_t)sinfo->fspace->serial_sect_count);
 #ifdef QAK
 HDfprintf(stderr, "%s: udata.sect_cnt_size = %u\n", FUNC, udata.sect_cnt_size);
 #endif /* QAK */
diff --git a/src/H5FSsection.c b/src/H5FSsection.c
index c589aa0..34da067 100644
--- a/src/H5FSsection.c
+++ b/src/H5FSsection.c
@@ -147,7 +147,7 @@ H5FS_sinfo_new(H5F_t *f, H5FS_t *fspace)
     sinfo->nbins = H5V_log2_gen(fspace->max_sect_size);
     sinfo->sect_prefix_size = H5FS_SINFO_PREFIX_SIZE(f);
     sinfo->sect_off_size = (fspace->max_sect_addr + 7) / 8;
-    sinfo->sect_len_size = (H5V_log2_gen(fspace->max_sect_size) + 7) / 8;
+    sinfo->sect_len_size = H5V_limit_enc_size((uint64_t)fspace->max_sect_size);
     sinfo->fspace = fspace;
 #ifdef QAK
 HDfprintf(stderr, "%s: sinfo->nbins = %u\n", FUNC, sinfo->nbins);
@@ -1300,7 +1300,7 @@ HDfprintf(stderr, "%s: fspace->sinfo->serial_size_count = %Zu\n", FUNC, fspace->
 HDfprintf(stderr, "%s: fspace->sinfo->serial_size_count = %Zu\n", FUNC, fspace->sinfo->serial_size_count);
 HDfprintf(stderr, "%s: fspace->serial_sect_count = %Hu\n", FUNC, fspace->serial_sect_count);
 #endif /* QAK */
-        sect_buf_size += fspace->sinfo->serial_size_count * MAX(1, ((H5V_log2_gen(fspace->serial_sect_count) + 7) / 8));
+        sect_buf_size += fspace->sinfo->serial_size_count * H5V_limit_enc_size((uint64_t)fspace->serial_sect_count);
 
         /* Size for each differently sized serializable section */
         sect_buf_size += fspace->sinfo->serial_size_count * fspace->sinfo->sect_len_size;
diff --git a/src/H5HFhdr.c b/src/H5HFhdr.c
index c1b856b..60d5002 100644
--- a/src/H5HFhdr.c
+++ b/src/H5HFhdr.c
@@ -225,7 +225,7 @@ H5HF_hdr_finish_init_phase1(H5HF_hdr_t *hdr)
 
     /* Set the size of heap IDs */
     hdr->heap_len_size = MIN(hdr->man_dtable.max_dir_blk_off_size,
-            ((H5V_log2_gen((uint64_t)hdr->max_man_size) + 7) / 8));
+            H5V_limit_enc_size((uint64_t)hdr->max_man_size));
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
diff --git a/src/H5Odtype.c b/src/H5Odtype.c
index ac07edf..ba343bc 100644
--- a/src/H5Odtype.c
+++ b/src/H5Odtype.c
@@ -232,10 +232,11 @@ H5O_dtype_decode_helper(H5F_t *f, const uint8_t **pp, H5T_t *dt)
         case H5T_COMPOUND:
             {
                 unsigned offset_nbytes;         /* Size needed to encode member offsets */
+                size_t max_memb_pos = 0;        /* Maximum member covered, so far */
                 unsigned j;
 
                 /* Compute the # of bytes required to store a member offset */
-                offset_nbytes = (H5V_log2_gen((uint64_t)dt->shared->size) + 7) / 8;
+                offset_nbytes = H5V_limit_enc_size((uint64_t)dt->shared->size);
 
                 /*
                  * Compound datatypes...
@@ -336,6 +337,18 @@ H5O_dtype_decode_helper(H5F_t *f, const uint8_t **pp, H5T_t *dt)
                     /* Set the field datatype (finally :-) */
                     dt->shared->u.compnd.memb[i].type = temp_type;
 
+                    /* Check if this field overlaps with a prior field */
+                    /* (probably indicates that the file is corrupt) */
+                    if(i > 0 && dt->shared->u.compnd.memb[i].offset < max_memb_pos) {
+                        for(j = 0; j < i; j++)
+                            if(dt->shared->u.compnd.memb[i].offset >= dt->shared->u.compnd.memb[j].offset
+                                    && dt->shared->u.compnd.memb[i].offset < (dt->shared->u.compnd.memb[j].offset + dt->shared->u.compnd.memb[j].size))
+                                HGOTO_ERROR(H5E_DATATYPE, H5E_CANTDECODE, FAIL, "member overlaps with previous member")
+                    } /* end if */
+
+                    /* Update the maximum member position covered */
+                    max_memb_pos = MAX(max_memb_pos, (dt->shared->u.compnd.memb[i].offset + dt->shared->u.compnd.memb[i].size));
+
                     /* Check if the datatype stayed packed */
                     if(dt->shared->u.compnd.packed) {
                         /* Check if the member type is packed */
@@ -734,7 +747,7 @@ H5O_dtype_encode_helper(const H5F_t *f, uint8_t **pp, const H5T_t *dt)
                 unsigned offset_nbytes;         /* Size needed to encode member offsets */
 
                 /* Compute the # of bytes required to store a member offset */
-                offset_nbytes = (H5V_log2_gen((uint64_t)dt->shared->size) + 7) / 8;
+                offset_nbytes = H5V_limit_enc_size((uint64_t)dt->shared->size);
 
                 /*
                  * Compound datatypes...
@@ -1097,7 +1110,7 @@ H5O_dtype_size(const H5F_t *f, const void *_mesg)
                 unsigned offset_nbytes;         /* Size needed to encode member offsets */
 
                 /* Compute the # of bytes required to store a member offset */
-                offset_nbytes = (H5V_log2_gen((uint64_t)dt->shared->size) + 7) / 8;
+                offset_nbytes = H5V_limit_enc_size((uint64_t)dt->shared->size);
 
                 /* Compute the total size needed to encode compound datatype */
                 for(u = 0; u < dt->shared->u.compnd.nmembs; u++) {
diff --git a/src/H5Vprivate.h b/src/H5Vprivate.h
index 94b3699..b92266c 100644
--- a/src/H5Vprivate.h
+++ b/src/H5Vprivate.h
@@ -410,5 +410,25 @@ H5V_log2_of2(uint32_t n)
     return(MultiplyDeBruijnBitPosition[(n * (uint32_t)0x077CB531UL) >> 27]);
 } /* H5V_log2_of2() */
 
+
+/*-------------------------------------------------------------------------
+ * Function:    H5V_limit_enc_size
+ *
+ * Purpose:     Determine the # of bytes needed to encode values within a
+ *              range from 0 to a given limit
+ *
+ * Return:      Number of bytes needed
+ *
+ * Programmer:  Quincey Koziol
+ *              Thursday, March 13, 2008
+ *
+ *-------------------------------------------------------------------------
+ */
+static H5_inline unsigned UNUSED
+H5V_limit_enc_size(uint64_t limit)
+{
+    return (H5V_log2_gen(limit) / 8) + 1;
+} /* end H5V_limit_enc_size() */
+
 #endif /* H5Vprivate_H */