[libvirt] [PATCH] conf: Report sensible error for invalid disk name

[Martin Kletzander]

The error "... but the cause is unknown" appeared for XMLs similar to
this:

 <disk type='file' device='cdrom'>
   <driver name='qemu' type='raw'/>
   <source file='/dev/zero'/>
   <target dev='sr0'/>
 </disk>

Notice unsupported disk type (for the driver), but also no address
specified. The first part is not a problem and we should not abort
immediately because of that, but the combination with the address
unknown was causing an unspecified error.
---
 src/util/util.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/util/util.c b/src/util/util.c
index 75b18c1..d5b2c97 100644
--- a/src/util/util.c
+++ b/src/util/util.c
@@ -2189,8 +2189,12 @@ int virDiskNameToIndex(const char *name) {
         }
     }

-    if (!ptr)
+    if (!ptr) {
+        virReportError(VIR_ERR_XML_ERROR,
+                       _("Unknown disk name '%s' and no address specified"),
+                       name);
         return -1;
+    }

     for (i = 0; *ptr; i++) {
         idx = (idx + (i < 1 ? 0 : 1)) * 26;
-- 
1.8.0