qmp: fill in the image field in BlockDeviceInfo

The image field in BlockDeviceInfo is supposed to contain an ImageInfo
object. However that is being filled in by bdrv_query_info(), not by
bdrv_block_device_info(), which is where BlockDeviceInfo is actually
created.

Anyone calling bdrv_block_device_info() directly will get a null image
field. As a consequence of this, the HMP command 'info block -n -v'
crashes QEMU.

This patch moves the code that fills in that field from
bdrv_query_info() to bdrv_block_device_info().

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 1429271563-3765-1-git-send-email-berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block.c b/block.c
index 002972a..101b50c 100644
--- a/block.c
+++ b/block.c
@@ -3897,15 +3897,20 @@
 }
 
 /* Put this QMP function here so it can access the static graph_bdrv_states. */
-BlockDeviceInfoList *bdrv_named_nodes_list(void)
+BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp)
 {
     BlockDeviceInfoList *list, *entry;
     BlockDriverState *bs;
 
     list = NULL;
     QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
+        BlockDeviceInfo *info = bdrv_block_device_info(bs, errp);
+        if (!info) {
+            qapi_free_BlockDeviceInfoList(list);
+            return NULL;
+        }
         entry = g_malloc0(sizeof(*entry));
-        entry->value = bdrv_block_device_info(bs);
+        entry->value = info;
         entry->next = list;
         list = entry;
     }