[svn-r761] Changes since 19981013

----------------------

./src/H5.c
	Fixed a signed vs. unsigned comparison.

./src/H5D.c
	Setting a fill value of all zeros will cause the fill value to
	be written to the dataset instead of relying on the low-level
	file driver initializing unwritten areas with zero.

./src/H5D.c
./src/H5F.c
./src/H5Fprivate.h
./src/H5G.c
./src/H5Gpkg.h
./src/H5Gprivate.h
./src/H5O.c
./src/H5T.c
	More file mounting stuff.

./src/H5I.c
	Fixed a bug where trying to close an invalid object id caused
	a core dump.  For instance, H5Gclose(-1).

./MANIFEST
./test/Makefile.in
./test/mount.c		[NEW]
	Mounting tests.

./src/H5R.c
	Fixed a couple (herr_t)NULL casts.

1 files changed, 11 insertions, 5 deletions

diff --git a/src/H5O.c b/src/H5O.c
index 233d7f5..4386962 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -244,7 +244,7 @@ H5O_open(H5G_entry_t *obj_ent)
 #endif
 
     /* Increment open-lock counters */
-    obj_ent->file->nopen++;
+    obj_ent->file->nopen_objs++;
     FUNC_LEAVE(SUCCEED);
 }
 
@@ -273,16 +273,16 @@ H5O_close(H5G_entry_t *obj_ent)
     /* Check args */
     assert(obj_ent);
     assert(obj_ent->file);
-    assert(obj_ent->file->nopen > 0);
+    assert(obj_ent->file->nopen_objs > 0);
 
     /* Decrement open-lock counters */
-    --obj_ent->file->nopen;
+    --obj_ent->file->nopen_objs;
 
     /*
      * If the file open-lock count has reached zero and the file has a close
      * pending then close the file.
      */
-    if (0 == obj_ent->file->nopen && obj_ent->file->close_pending) {
+    if (0 == obj_ent->file->nopen_objs && obj_ent->file->close_pending) {
 	H5F_close(obj_ent->file);
     }
 #ifdef H5O_DEBUG
@@ -1203,8 +1203,14 @@ H5O_modify(H5G_entry_t *ent, const H5O_class_t *type, intn overwrite,
 	    } else {
 		/*
 		 * The shared message is stored in some other object header.
-		 * Increment the reference count on that object header.
+		 * The other object header must be in the same file as the
+		 * new object header. Increment the reference count on that
+		 * object header.
 		 */
+		if (sh_mesg->u.ent.file->shared != ent->file->shared) {
+		    HGOTO_ERROR(H5E_OHDR, H5E_LINK, FAIL,
+				"interfile hard links are not allowed");
+		}
 		if (H5O_link (&(sh_mesg->u.ent), 1)<0) {
 		    HGOTO_ERROR (H5E_OHDR, H5E_LINK, FAIL,
 				 "unable to adjust shared object link count");