Fix SWMR/refresh bug hidden by library free lists (#1702) (#1711)

src/H5Oflush.c

@@ -280,8 +280,9 @@ H5Orefresh(hid_t oid)
 herr_t
 H5O_refresh_metadata(hid_t oid, H5O_loc_t oloc)
 {
-    H5VL_object_t *vol_obj   = NULL;    /* VOL object associated with the ID */
-    hbool_t        objs_incr = FALSE;   /* Whether the object count in the file was incremented */
+    H5VL_object_t *vol_obj   = NULL;  /* VOL object associated with the ID */
+    hbool_t        objs_incr = FALSE; /* Whether the object count in the file was incremented */
+    H5F_t *        file      = NULL;
     herr_t         ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -294,6 +295,11 @@ H5O_refresh_metadata(hid_t oid, H5O_loc_t oloc)
         H5O_shared_t cached_H5O_shared;
         H5VL_t *     connector = NULL;
 
+        /* Hold a copy of the object's file pointer, since closing the object will
+         * invalidate the file pointer in the oloc.
+         */
+        file = oloc.file;
+
         /* Create empty object location */
         obj_loc.oloc = &obj_oloc;
         obj_loc.path = &obj_path;
@@ -342,8 +348,8 @@ H5O_refresh_metadata(hid_t oid, H5O_loc_t oloc)
     } /* end if */
 
 done:
-    if (objs_incr)
-        H5F_decr_nopen_objs(oloc.file);
+    if (objs_incr && file)
+        H5F_decr_nopen_objs(file);
 
     FUNC_LEAVE_NOAPI(ret_value);
 } /* end H5O_refresh_metadata() */