[svn-r14402] Description:

	Add work-around to allow reading files that were produced with a buggy
earlier version of the library, which could create objects with the wrong
object header message count.  There is now a configure flag
"--enable-strict-format-checks" which triggers a failure on reading a file
with this sort of corruption (when enabled) and allows the object to be read
(when disabled).  The default value for the "strict-format-checks" flag is
yes when the "debug" flag is enabled and no when the "debug" flag is disabled.

	Note that if strict format checks are disabled (allowing objects with
this particular kind of corruption to be read) and the file is opened with
write access, the library will re-write the object header for the corrupt
object with the correct # of object header messages.

	This closes bugzilla bug #1010.

Tested on:
        FreeBSD/32 6.2 (duty) in debug mode
        FreeBSD/64 6.2 (liberty) w/C++ & FORTRAN, in debug mode
        Linux/32 2.6 (kagiso) w/PGI compilers, w/C++ & FORTRAN, w/threadsafe,
                                in debug mode
        Linux/64-amd64 2.6 (smirom) w/default API=1.6.x, w/C++ & FORTRAN,
                                in production mode
        Linux/64-ia64 2.6 (cobalt) w/Intel compilers, w/C++ & FORTRAN,
                                in production mode
        Solaris/32 2.10 (linew) w/deprecated symbols disabled, w/C++ & FORTRAN,
                                w/szip filter, in production mode
        Mac OS X/32 10.4.10 (amazon) in debug mode
        Linux/64-ia64 2.4 (tg-login3) w/parallel, w/FORTRAN, in production mode

6 files changed, 43 insertions, 1 deletions

diff --git a/src/H5O.c b/src/H5O.c
index fc00813..c615437 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -1077,6 +1077,14 @@ H5O_create(H5F_t *f, hid_t dxpl_id, size_t size_hint, hid_t ocpl_id,
         oh->version = H5O_VERSION_1;
     oh->sizeof_size = H5F_SIZEOF_SIZE(f);
     oh->sizeof_addr = H5F_SIZEOF_ADDR(f);
+#ifdef H5O_ENABLE_BAD_MESG_COUNT
+    /* Check whether the "bad message count" property is set */
+    if(H5P_exist_plist(oc_plist, H5O_BAD_MESG_COUNT_NAME) > 0) {
+        /* Retrieve bad message count flag */
+        if(H5P_get(oc_plist, H5O_BAD_MESG_COUNT_NAME, &oh->store_bad_mesg_count) < 0)
+            HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't get bad message count flag")
+    } /* end if */
+#endif /* H5O_ENABLE_BAD_MESG_COUNT */
 
     /* Set initial status flags */
     oh->flags = oh_flags;
diff --git a/src/H5Ocache.c b/src/H5Ocache.c
index b5c8c7d..0d5765e 100644
--- a/src/H5Ocache.c
+++ b/src/H5Ocache.c
@@ -580,10 +580,25 @@ H5O_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void UNUSED * _udata1,
     if(merged_null_msgs)
 	oh->cache_info.is_dirty = TRUE;
 
+/* Don't check for the incorrect # of object header messages bug unless we've
+ * enabled strict format checking.  This allows for older files, created with
+ * a version of the library that had a bug in tracking the correct # of header
+ * messages to be read in without the library fussing about things. -QAK
+ */
+#ifdef H5_STRICT_FORMAT_CHECKS
     /* Sanity check for the correct # of messages in object header */
     if(oh->version == H5O_VERSION_1)
         if((oh->nmesgs + merged_null_msgs) != nmesgs)
             HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "corrupt object header - too few messages")
+#else /* H5_STRICT_FORMAT_CHECKS */
+    /* Check for incorrect # of messages in object header and if we have write
+     * access on the file, flag the object header as dirty, so it gets fixed. 
+     */
+    if(oh->version == H5O_VERSION_1)
+        if((oh->nmesgs + merged_null_msgs) != nmesgs &&
+                (H5F_get_intent(f) & H5F_ACC_RDWR))
+            oh->cache_info.is_dirty = TRUE;
+#endif /* H5_STRICT_FORMAT_CHECKS */
 
 #ifdef H5O_DEBUG
 H5O_assert(oh);
@@ -710,7 +725,12 @@ H5O_assert(oh);
             *p++ = 0;
 
             /* Number of messages */
-            UINT16ENCODE(p, oh->nmesgs);
+#ifdef H5O_ENABLE_BAD_MESG_COUNT
+            if(oh->store_bad_mesg_count)
+                UINT16ENCODE(p, (oh->nmesgs - 1))
+            else
+#endif /* H5O_ENABLE_BAD_MESG_COUNT */
+                UINT16ENCODE(p, oh->nmesgs);
 
             /* Link count */
             UINT32ENCODE(p, oh->nlink);
diff --git a/src/H5Opkg.h b/src/H5Opkg.h
index c90ff0a..e2c5661 100644
--- a/src/H5Opkg.h
+++ b/src/H5Opkg.h
@@ -253,6 +253,12 @@ struct H5O_t {
     /* File-specific information (not stored) */
     size_t      sizeof_size;            /* Size of file sizes 		     */
     size_t      sizeof_addr;            /* Size of file addresses	     */
+#ifdef H5O_ENABLE_BAD_MESG_COUNT
+    hbool_t     store_bad_mesg_count;   /* Flag to indicate that a bad message count should be stored */
+                                        /* (This is to simulate a bug in earlier
+                                         *      versions of the library)
+                                         */
+#endif /* H5O_ENABLE_BAD_MESG_COUNT */
 
     /* Object information (stored) */
     hbool_t     has_refcount_msg;       /* Whether the object has a ref. count message */
diff --git a/src/H5Oprivate.h b/src/H5Oprivate.h
index 72d9e2d..4a55ac2 100644
--- a/src/H5Oprivate.h
+++ b/src/H5Oprivate.h
@@ -91,6 +91,10 @@ typedef struct H5O_t H5O_t;
 #define H5O_BOGUS_MSG_FLAGS_NAME        "bogus msg flags"       /* Flags for 'bogus' message */
 #define H5O_BOGUS_MSG_FLAGS_SIZE        sizeof(uint8_t)
 #endif /* H5O_ENABLE_BOGUS */
+#ifdef H5O_ENABLE_BAD_MESG_COUNT
+#define H5O_BAD_MESG_COUNT_NAME         "bad message count"       /* Flag setting bad message count */
+#define H5O_BAD_MESG_COUNT_SIZE         sizeof(hbool_t)
+#endif /* H5O_ENABLE_BAD_MESG_COUNT */
 
 /* ========= Object Copy properties ============ */
 #define H5O_CPY_OPTION_NAME 		"copy object"           /* Copy options */
diff --git a/src/H5config.h.in b/src/H5config.h.in
index 0c89e98..5c767ef 100644
--- a/src/H5config.h.in
+++ b/src/H5config.h.in
@@ -570,6 +570,9 @@
 /* Define to 1 if you have the ANSI C header files. */
 #undef STDC_HEADERS
 
+/* Define if strict file format checks are enabled */
+#undef STRICT_FORMAT_CHECKS
+
 /* Define if your system supports pthread_attr_setscope(&attribute,
    PTHREAD_SCOPE_SYSTEM) call. */
 #undef SYSTEM_SCOPE_THREADS
diff --git a/src/Makefile.in b/src/Makefile.in
index 44bc4e7..e733039 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -269,6 +269,7 @@ SET_MAKE = @SET_MAKE@
 SHELL = /bin/sh
 SIZE_T = @SIZE_T@
 STATIC_SHARED = @STATIC_SHARED@
+STRICT_FORMAT_CHECKS = @STRICT_FORMAT_CHECKS@
 STRIP = @STRIP@
 TESTPARALLEL = @TESTPARALLEL@
 TIME = @TIME@