bdrv_refresh_filename() should simply skip all implicit nodes.  They are
supposed to be invisible to the user, so they should not appear in
filename information.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
---
 block.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/block.c b/block.c
index 0e3d29d378..96fed5d7e6 100644
--- a/block.c
+++ b/block.c
@@ -5488,6 +5488,20 @@ void bdrv_refresh_filename(BlockDriverState *bs)
         bdrv_refresh_filename(child->bs);
     }
 
+    if (bs->implicit) {
+        /* For implicit nodes, just copy everything from the single child */
+        child = QLIST_FIRST(&bs->children);
+        assert(QLIST_NEXT(child, next) == NULL);
+
+        pstrcpy(bs->exact_filename, sizeof(bs->exact_filename),
+                child->bs->exact_filename);
+        pstrcpy(bs->filename, sizeof(bs->filename), child->bs->filename);
+
+        bs->full_open_options = qobject_ref(child->bs->full_open_options);
+
+        return;
+    }
+
     if (drv->bdrv_refresh_filename) {
         /* Obsolete information is of no use here, so drop the old file name
          * information before refreshing it */
-- 
2.20.1