[svn-r16611] In previous checkin (r16609), the flag "write_driver" wasn't necessary as Quincey pointed out.

I took it out and used the driver address instead.

Tested on jam - simple change.

3 files changed, 9 insertions, 13 deletions

diff --git a/src/H5F.c b/src/H5F.c
index 6ca852a..e7b4cd3 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -891,7 +891,6 @@ H5F_new(H5F_file_t *shared, hid_t fcpl_id, hid_t fapl_id, H5FD_t *lf)
         for(u = 0; u < NELMTS(f->shared->fs_addr); u++)
             f->shared->fs_addr[u] = HADDR_UNDEF;
 	f->shared->driver_addr = HADDR_UNDEF;
-	f->shared->write_driver = TRUE;
 	f->shared->accum.loc = HADDR_UNDEF;
         f->shared->lf = lf;
 
diff --git a/src/H5Fpkg.h b/src/H5Fpkg.h
index 6434017..4080705 100644
--- a/src/H5Fpkg.h
+++ b/src/H5Fpkg.h
@@ -134,7 +134,6 @@ typedef struct H5F_file_t {
     unsigned	sohm_vers;	/* Version of shared message table on disk */
     unsigned	sohm_nindexes;	/* Number of shared messages indexes in the table */
     haddr_t	driver_addr;	/* File driver information block address*/
-    hbool_t     write_driver;   /* Whether to write file driver block in the superblock */
     unsigned long feature_flags; /* VFL Driver feature Flags            */
     haddr_t	maxaddr;	/* Maximum address for file             */
 
diff --git a/src/H5Fsuper.c b/src/H5Fsuper.c
index 69c7a8d..04abfb2 100644
--- a/src/H5Fsuper.c
+++ b/src/H5Fsuper.c
@@ -466,16 +466,6 @@ H5F_super_read(H5F_t *f, hid_t dxpl_id, H5G_loc_t *root_loc)
             if(H5FD_sb_decode(lf, drv_name, p) < 0)
                 HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to decode driver information")
         } /* end if */
-        else
-            /* This flag is false only if a file was created with v1.6 library or 
-             * before and no driver info was saved in the superblock.  When the file is
-             * closed and superblock is written to the file, v1.8 library or after 
-             * doesn't write the driver info in the superblock.  Otherwise, the newly 
-             * added driver block will overwrite the (meta)data right after the 
-             * superblock. SLU - 2009/3/24
-             */  
-            shared->write_driver = FALSE;
-
     } /* end if */
     else {
         haddr_t root_addr;              /* Address of root group */
@@ -944,7 +934,15 @@ H5F_super_write(H5F_t *f, hid_t dxpl_id)
 
         /* Encode the driver information block. */
         H5_ASSIGN_OVERFLOW(driver_size, H5FD_sb_size(f->shared->lf), hsize_t, size_t);
-        if(driver_size > 0 && f->shared->write_driver) {
+
+        /* Checking whether driver block address is defined here is to handle backward
+         * compatibility.  If the file was created with v1.6 library or earlier and no
+         * driver info block was written in the superblock, we don't write it either even
+         * though there's some driver info.  Otherwise, the driver block extended will
+         * overwrite the (meta)data right after the superblock. This situation happens to
+         * the family driver particularly.  SLU - 2009/3/24 
+         */
+        if(driver_size > 0 && H5F_addr_defined(f->shared->driver_addr)) {
             char driver_name[9];    /* Name of driver, for driver info block */
             uint8_t *dbuf = p;      /* Pointer to beginning of driver info */