schema: do not require name for certain pool types

Pool types that have the VIR_STORAGE_POOL_SOURCE_NAME flag set
allow omitting the <name> element and instead fill out the pool name
from the <source><name> element.

Relax the schema to make <name> optional for these pools.
Expressing that at least one of these is required is out of scope
of the schema.

(cherry picked from commit 8ef12b96)

docs/schemas/storagepool.rng

@@ -69,7 +69,7 @@
       <value>logical</value>
     </attribute>
     <interleave>
-      <ref name='commonmetadata'/>
+      <ref name='commonMetadataNameOptional'/>
       <ref name='sizing'/>
       <ref name='sourcelogical'/>
       <ref name='targetlogical'/>
@@ -131,7 +131,7 @@
       <value>rbd</value>
     </attribute>
     <interleave>
-      <ref name='commonmetadata'/>
+      <ref name='commonMetadataNameOptional'/>
       <ref name='sizing'/>
       <ref name='sourcerbd'/>
     </interleave>
@@ -142,7 +142,7 @@
       <value>sheepdog</value>
     </attribute>
     <interleave>
-      <ref name='commonmetadata'/>
+      <ref name='commonMetadataNameOptional'/>
       <ref name='sizing'/>
       <ref name='sourcesheepdog'/>
     </interleave>
@@ -153,7 +153,7 @@
       <value>gluster</value>
     </attribute>
     <interleave>
-      <ref name='commonmetadata'/>
+      <ref name='commonMetadataNameOptional'/>
       <ref name='sizing'/>
       <ref name='sourcegluster'/>
     </interleave>
@@ -164,7 +164,7 @@
       <value>zfs</value>
     </attribute>
     <interleave>
-      <ref name='commonmetadata'/>
+      <ref name='commonMetadataNameOptional'/>
       <ref name='sizing'/>
       <ref name='sourcezfs'/>
       <optional>
@@ -192,6 +192,21 @@
     </interleave>
   </define>
 
+  <define name='commonMetadataNameOptional'>
+    <interleave>
+      <optional>
+        <element name='name'>
+          <ref name='genericName'/>
+        </element>
+      </optional>
+      <optional>
+        <element name='uuid'>
+          <ref name='UUID'/>
+        </element>
+      </optional>
+    </interleave>
+  </define>
+
   <define name='commonmetadata'>
     <interleave>
       <element name='name'>

tests/storagepoolxml2xmlin/pool-logical-noname.xml

+<pool type='logical'>
+  <uuid>1c13165a-d0f4-3aee-b447-30fb38789091</uuid>
+  <capacity>99891544064</capacity>
+  <allocation>99220455424</allocation>
+  <available>671088640</available>
+  <source>
+    <name>zily</name>
+    <format type='lvm2'/>
+  </source>
+  <target>
+    <path>/dev/zily</path>
+    <permissions>
+      <mode>0700</mode>
+      <owner>0</owner>
+      <group>0</group>
+    </permissions>
+  </target>
+</pool>