qcow2: fix null pointer dereference

It seems this assert() was somehow misplaced.

block/qcow2-refcount.c:2193:42: warning: Array access (from variable 'on_disk_reftable') results in a null pointer dereference
        on_disk_reftable[refblock_index] = refblock_offset;
        ~~~~~~~~~~~~~~~~                 ^

Reported-by: Clang Static Analyzer
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

1 files changed, 2 insertions, 2 deletions

diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index c9b0dcb4f3..168fc32e7b 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -2189,6 +2189,8 @@ write_refblocks:
              * this will leak that range, but we can easily fix that by running
              * a leak-fixing check after this rebuild operation */
             reftable_offset = -1;
+        } else {
+            assert(on_disk_reftable);
         }
         on_disk_reftable[refblock_index] = refblock_offset;
 
@@ -2258,8 +2260,6 @@ write_refblocks:
         goto write_refblocks;
     }
 
-    assert(on_disk_reftable);
-
     for (refblock_index = 0; refblock_index < reftable_size; refblock_index++) {
         cpu_to_be64s(&on_disk_reftable[refblock_index]);
     }