conf: Make backing store index optional

Index will remain an internal property even if we allow backing store
parsing from the XML, so we need to allow backing store without it in
the schema.

diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index 4dbda6932da84268d7cc1f0f14d0b463c073c419..874af3ffa3f5211948a4b19b0866b8375db8118e 100644 (file)
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -1415,9 +1415,11 @@
 
   <define name="diskBackingStore">
     <element name="backingStore">
-      <attribute name="index">
-        <ref name="positiveInteger"/>
-      </attribute>
+      <optional>
+        <attribute name="index">
+          <ref name="positiveInteger"/>
+        </attribute>
+      </optional>
       <interleave>
         <ref name="diskSource"/>
         <ref name="diskBackingChain"/>