[PATCH-for-5.0] block: Assert BlockDriver::format_name is not NULL

[Philippe Mathieu-Daudé]

bdrv_do_find_format() calls strcmp() using BlockDriver::format_name
as argument, which must not be NULL. Assert this field is not null
when we register a block driver in bdrv_register().

Reported-by: Mansour Ahmadi <address@hidden>
Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
---
 block.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/block.c b/block.c
index a2542c977b..6b984dc883 100644
--- a/block.c
+++ b/block.c
@@ -363,6 +363,7 @@ char *bdrv_get_full_backing_filename(BlockDriverState *bs, 
Error **errp)
 
 void bdrv_register(BlockDriver *bdrv)
 {
+    assert(bdrv->format_name);
     QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list);
 }
 
-- 
2.21.1