[svn-r16514] Description:

	Merge r16440:16500 from trunk into revise_chunks branch.

Tested on:
        FreeBSD/32 6.3 (duty) in debug mode
        FreeBSD/64 6.3 (liberty) w/C++ & FORTRAN, in debug mode
        Linux/32 2.6 (jam) w/PGI compilers, w/C++ & FORTRAN, w/threadsafe,
                                in debug mode
        Linux/64-amd64 2.6 (smirom) w/Intel compilers w/default API=1.6.x,
                                w/C++ & FORTRAN, in production mode
        Solaris/32 2.10 (linew) w/deprecated symbols disabled, w/C++ & FORTRAN,
                                w/szip filter, in production mode
        Linux/64-ia64 2.6 (cobalt) w/Intel compilers, w/C++ & FORTRAN,
                                in production mode
        Linux/64-ia64 2.4 (tg-login3) w/parallel, w/FORTRAN, in production mode
        Linux/64-amd64 2.6 (abe) w/parallel, w/FORTRAN, in production mode
        Mac OS X/32 10.5.6 (amazon) in debug mode
        Mac OS X/32 10.5.6 (amazon) w/C++ & FORTRAN, w/threadsafe,
                                in production mode

1 files changed, 35 insertions, 12 deletions

diff --git a/src/H5Oshared.c b/src/H5Oshared.c
index 062443a..fd7cc8b 100644
--- a/src/H5Oshared.c
+++ b/src/H5Oshared.c
@@ -107,7 +107,7 @@
  *-------------------------------------------------------------------------
  */
 static void *
-H5O_shared_read(H5F_t *f, hid_t dxpl_id, unsigned *ioflags,
+H5O_shared_read(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh, unsigned *ioflags,
     const H5O_shared_t *shared, const H5O_msg_class_t *type)
 {
     H5HF_t *fheap = NULL;
@@ -159,7 +159,7 @@ H5O_shared_read(H5F_t *f, hid_t dxpl_id, unsigned *ioflags,
             HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "can't read message from fractal heap.")
 
         /* Decode the message */
-        if(NULL == (ret_value = (type->decode)(f, dxpl_id, 0, ioflags, mesg_ptr)))
+        if(NULL == (ret_value = (type->decode)(f, dxpl_id, open_oh, 0, ioflags, mesg_ptr)))
             HGOTO_ERROR(H5E_OHDR, H5E_CANTDECODE, NULL, "can't decode shared message.")
     } /* end if */
     else {
@@ -167,12 +167,22 @@ H5O_shared_read(H5F_t *f, hid_t dxpl_id, unsigned *ioflags,
 
         HDassert(shared->type == H5O_SHARE_TYPE_COMMITTED);
 
-        /* Get the shared message from an object header */
+        /* Build the object location for the shared message's object header */
         oloc.file = f;
         oloc.addr = shared->u.loc.oh_addr;
         oloc.holding_file = FALSE;
-        if(NULL == (ret_value = H5O_msg_read(&oloc, type->id, NULL, dxpl_id)))
-            HGOTO_ERROR(H5E_OHDR, H5E_READERROR, NULL, "unable to read message")
+
+        if(open_oh && oloc.addr == H5O_OH_GET_ADDR(open_oh)) {
+            /* The shared message is in the already opened object header.  This
+             * is possible, for example, if an attribute's datatype is shared in
+             * the same object header the attribute is in.  Read the message
+             * directly. */
+            if(NULL == (ret_value = H5O_msg_read_oh(f, dxpl_id, open_oh, type->id, NULL)))
+                HGOTO_ERROR(H5E_OHDR, H5E_READERROR, NULL, "unable to read message")
+        } else
+            /* The shared message is in another object header */
+            if(NULL == (ret_value = H5O_msg_read(&oloc, type->id, NULL, dxpl_id)))
+                HGOTO_ERROR(H5E_OHDR, H5E_READERROR, NULL, "unable to read message")
     } /* end else */
 
     /* Mark the message as shared */
@@ -228,7 +238,7 @@ H5O_shared_link_adj(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh,
         H5O_loc_t oloc;         /* Location for object header where message is stored */
 
         /*
-         * The shared message is stored in some other object header.
+         * The shared message is stored in some object header.
          * The other object header must be in the same file as the
          * new object header. Adjust the reference count on that
          * object header.
@@ -236,13 +246,26 @@ H5O_shared_link_adj(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh,
         if(shared->file->shared != f->shared)
             HGOTO_ERROR(H5E_LINK, H5E_CANTINIT, FAIL, "interfile hard links are not allowed")
 
-        /* Get the shared message from an object header */
+        /* Build the object location for the shared message's object header */
         oloc.file = f;
         oloc.addr = shared->u.loc.oh_addr;
         oloc.holding_file = FALSE;
 
-        if(H5O_link(&oloc, adjust, dxpl_id) < 0)
-            HGOTO_ERROR(H5E_OHDR, H5E_LINKCOUNT, FAIL, "unable to adjust shared object link count")
+        if(open_oh && oloc.addr == H5O_OH_GET_ADDR(open_oh)) {
+            /* The shared message is in the already opened object header.  This
+             * is possible, for example, if an attribute's datatype is shared in
+             * the same object header the attribute is in.  Adjust the link
+             * count directly. */
+            unsigned oh_flags = H5AC__NO_FLAGS_SET; /* This is used only to satisfy H5O_link_oh */
+
+            if(H5O_link_oh(f, adjust, dxpl_id, open_oh, &oh_flags) < 0)
+                HGOTO_ERROR(H5E_OHDR, H5E_LINKCOUNT, FAIL, "unable to adjust shared object link count")
+
+            HDassert(!(oh_flags & H5AC__DELETED_FLAG));
+        } else
+            /* The shared message is in another object header */
+            if(H5O_link(&oloc, adjust, dxpl_id) < 0)
+                HGOTO_ERROR(H5E_OHDR, H5E_LINKCOUNT, FAIL, "unable to adjust shared object link count")
     } /* end if */
     else {
         HDassert(shared->type == H5O_SHARE_TYPE_SOHM || shared->type == H5O_SHARE_TYPE_HERE);
@@ -277,7 +300,7 @@ done:
  *-------------------------------------------------------------------------
  */
 void *
-H5O_shared_decode(H5F_t *f, hid_t dxpl_id, unsigned *ioflags,
+H5O_shared_decode(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh, unsigned *ioflags,
     const uint8_t *buf, const H5O_msg_class_t *type)
 {
     H5O_shared_t sh_mesg;       /* Shared message info */
@@ -344,7 +367,7 @@ H5O_shared_decode(H5F_t *f, hid_t dxpl_id, unsigned *ioflags,
     sh_mesg.msg_type_id = type->id;
 
     /* Retrieve actual message, through decoded shared message info */
-    if(NULL == (ret_value = H5O_shared_read(f, dxpl_id, ioflags, &sh_mesg, type)))
+    if(NULL == (ret_value = H5O_shared_read(f, dxpl_id, open_oh, ioflags, &sh_mesg, type)))
         HGOTO_ERROR(H5E_OHDR, H5E_READERROR, NULL, "unable to retrieve native message")
 
 done:
@@ -708,7 +731,7 @@ H5O_shared_debug(const H5O_shared_t *mesg, FILE *stream, int indent, int fwidth)
                     "SOHM");
             HDfprintf(stream, "%*s%-*s %016llx\n", indent, "", fwidth,
                     "Heap ID:",
-                    (unsigned long_long)mesg->u.heap_id);
+                    (unsigned long long)mesg->u.heap_id);
             break;
 
         case H5O_SHARE_TYPE_HERE: