qemu: blockjob: Transfer 'readonly' state of images after active layer block commit

When commiting a different image becomes the disk source. Since we store
the readonly flag per-image we must update it to the same state the
original image had.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

src/qemu/qemu_blockjob.c

@@ -1106,6 +1106,7 @@ qemuBlockJobProcessEventCompletedActiveCommit(virQEMUDriverPtr driver,
         cfgbase = cfgbaseparent->backingStore;
         cfgbaseparent->backingStore = NULL;
         cfgdisk->src = cfgbase;
+        cfgdisk->src->readonly = cfgtop->readonly;
         virObjectUnref(cfgtop);
     }
 
@@ -1115,6 +1116,7 @@ qemuBlockJobProcessEventCompletedActiveCommit(virQEMUDriverPtr driver,
 
     baseparent->backingStore = NULL;
     job->disk->src = job->data.commit.base;
+    job->disk->src->readonly = job->data.commit.top->readonly;
 
     qemuBlockJobEventProcessConcludedRemoveChain(driver, vm, asyncJob, job->data.commit.top);
     virObjectUnref(job->data.commit.top);