[Qemu-block] [PATCH] block jobs: Improve error message for missing job ID

[Kevin Wolf]

If a block job is started with a node name rather than a device name and
no explicit job ID is passed, it was reported that '' isn't a
well-formed ID. Which is correct, but we can make the message a little
bit nicer.

Signed-off-by: Kevin Wolf <address@hidden>
---
 blockjob.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/blockjob.c b/blockjob.c
index a5ba3be..a167f96 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -132,6 +132,10 @@ void *block_job_create(const char *job_id, const 
BlockJobDriver *driver,
 
     if (job_id == NULL) {
         job_id = bdrv_get_device_name(bs);
+        if (!*job_id) {
+            error_setg(errp, "An explicit job ID is required for this node");
+            return NULL;
+        }
     }
 
     if (!id_wellformed(job_id)) {
-- 
1.8.3.1