[svn-r16594] Purpose: fix bug 1189

Description:
Some files apparently exist in the wild which have corrupt symbol table messages
on the root group.  These files can be opened by 1.6 (which uses the cached
information in the superblock) but not by 1.8.  This patch fixes 1.8 and 1.9 so
they can now open these files, and will correct them if necessary.  Also fix
some potential (rare) problems with array datatype versions.

Tested: jam (parallel; h5committest not working on linew or smirom)

1 files changed, 44 insertions, 7 deletions

diff --git a/src/H5Odtype.c b/src/H5Odtype.c
index 60f77d9..fe8c627 100644
--- a/src/H5Odtype.c
+++ b/src/H5Odtype.c
@@ -115,20 +115,23 @@ const H5O_msg_class_t H5O_MSG_DTYPE[1] = {{
  *
  * Purpose:	Decodes a datatype
  *
- * Return:	Non-negative on success/Negative on failure
+ * Return:	TRUE if we can upgrade the parent type's version even
+ *                  with strict format checks
+ *              FALSE if we cannot
+ *              Negative on failure
  *
  * Programmer:	Robb Matzke
  *		Monday, December  8, 1997
  *
  *-------------------------------------------------------------------------
  */
-static herr_t
+static htri_t
 H5O_dtype_decode_helper(H5F_t *f, unsigned *ioflags/*in,out*/, const uint8_t **pp, H5T_t *dt)
 {
     unsigned	flags, version;
     unsigned	i;
     size_t	z;
-    herr_t      ret_value = SUCCEED;       /* Return value */
+    htri_t      ret_value = FALSE;       /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT(H5O_dtype_decode_helper)
 
@@ -254,6 +257,7 @@ H5O_dtype_decode_helper(H5F_t *f, unsigned *ioflags/*in,out*/, const uint8_t **p
                 unsigned offset_nbytes;         /* Size needed to encode member offsets */
                 size_t max_memb_pos = 0;        /* Maximum member covered, so far */
                 unsigned max_version = 0;       /* Maximum member version */
+                hbool_t upgrade_to = 0;         /* Version number we can "soft" upgrade to */
                 unsigned j;
 
                 /* Compute the # of bytes required to store a member offset */
@@ -271,6 +275,7 @@ H5O_dtype_decode_helper(H5F_t *f, unsigned *ioflags/*in,out*/, const uint8_t **p
                     HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")
                 for(i = 0; i < dt->shared->u.compnd.nmembs; i++) {
                     unsigned ndims = 0;     /* Number of dimensions of the array field */
+                    htri_t can_upgrade;     /* Whether we can upgrade this type's version */
                     hsize_t dim[H5O_LAYOUT_NDIMS];  /* Dimensions of the array */
                     H5T_t *array_dt;    /* Temporary pointer to the array datatype */
                     H5T_t *temp_type;   /* Temporary pointer to the field's datatype */
@@ -318,16 +323,20 @@ H5O_dtype_decode_helper(H5F_t *f, unsigned *ioflags/*in,out*/, const uint8_t **p
                         HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")
 
                     /* Decode the field's datatype information */
-                    if(H5O_dtype_decode_helper(f, ioflags, pp, temp_type) < 0) {
+                    if((can_upgrade = H5O_dtype_decode_helper(f, ioflags, pp, temp_type)) < 0) {
                         for(j = 0; j <= i; j++)
                             H5MM_xfree(dt->shared->u.compnd.memb[j].name);
                         H5MM_xfree(dt->shared->u.compnd.memb);
                         HGOTO_ERROR(H5E_DATATYPE, H5E_CANTDECODE, FAIL, "unable to decode member type")
                     } /* end if */
 
-                    /* Keep track of the maximum member version found */
-                    if(temp_type->shared->version > max_version)
-                        max_version = temp_type->shared->version;
+                    /* Upgrade the version if we can and it is necessary */
+                    if(can_upgrade && temp_type->shared->version > version) {
+                        upgrade_to = temp_type->shared->version;
+
+                        /* Pass "can_upgrade" flag down to parent type */
+                        ret_value = TRUE;
+                    } /* end if */
 
                     /* Go create the array datatype now, for older versions of the datatype message */
                     if(version == H5O_DTYPE_VERSION_1) {
@@ -346,9 +355,26 @@ H5O_dtype_decode_helper(H5F_t *f, unsigned *ioflags/*in,out*/, const uint8_t **p
 
                             /* Make the array type the type that is set for the field */
                             temp_type = array_dt;
+
+                            /* Reset array version if NOCHANGE is specified (i.e. h5debug) */
+                            if(*ioflags & H5O_DECODEIO_NOCHANGE)
+                                temp_type->shared->version = H5O_DTYPE_VERSION_1;
+                            else {
+                                /* Otherwise upgrade the compound version */
+                                if(upgrade_to < temp_type->shared->version)
+                                    upgrade_to = temp_type->shared->version;
+
+                                /* Set the return value to indicate that we should freely
+                                 * upgrade parent types */
+                                ret_value = TRUE;
+                            } /* end else */
                         } /* end if */
                     } /* end if */
 
+                    /* Keep track of the maximum member version found */
+                    if(temp_type->shared->version > max_version)
+                        max_version = temp_type->shared->version;
+
                     /*
                      * Set the "force conversion" flag if VL datatype fields exist in this
                      * type or any component types
@@ -397,6 +423,17 @@ H5O_dtype_decode_helper(H5F_t *f, unsigned *ioflags/*in,out*/, const uint8_t **p
                             dt->shared->u.compnd.packed = FALSE;
                     } /* end if */
                 } /* end for */
+
+                /* Upgrade the compound if requested */
+                if(version < upgrade_to) {
+                    version = upgrade_to;
+                    if(H5T_upgrade_version(dt, upgrade_to) < 0)
+                        HGOTO_ERROR(H5E_DATATYPE, H5E_CANTSET, FAIL, "can't upgrade compound encoding version")
+                    /* We won't mark the message dirty since there were no
+                     * errors in the file, simply type versions that we will no
+                     * longer encode. */
+                } /* end if */
+
                 /* Check that no member of this compound has a version greater
                  * than the compound itself. */
                 H5O_DTYPE_CHECK_VERSION(dt, version, max_version, ioflags, "compound", FAIL)