conf: Remove duplicate entries in <metadata> by namespace

Since the APIs support just one element per namespace and while
modifying an element all duplicates would be removed, let's do this
right away in the post parse callback.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1190590

src/conf/domain_conf.c

@@ -3148,6 +3148,45 @@ virDomainDefRejectDuplicateControllers(virDomainDefPtr def)
 }
 
 
+/**
+ * virDomainDefRemoveDuplicateMetadata:
+ * @def: Remove duplicate metadata for this def
+ *
+ * This function removes metadata elements in @def that share the namespace.
+ * The first metadata entry of every duplicate namespace is kept.
+ */
+static void
+virDomainDefRemoveDuplicateMetadata(virDomainDefPtr def)
+{
+    xmlNodePtr child;
+    xmlNodePtr next;
+
+    if (!def || !def->metadata)
+        return;
+
+    for (child = def->metadata->children; child; child = child->next) {
+        /* check that every other child of @root doesn't share the namespace of
+         * the current one and delete them possibly */
+        next = child->next;
+        while (next) {
+            xmlNodePtr dupl = NULL;
+
+            if (child->ns && next->ns &&
+                STREQ_NULLABLE((const char *) child->ns->href,
+                               (const char *) next->ns->href))
+                dupl = next;
+
+            next = next->next;
+
+            if (dupl) {
+                xmlUnlinkNode(dupl);
+                xmlFreeNode(dupl);
+            }
+        }
+    }
+}
+
+
 static int
 virDomainDefPostParseInternal(virDomainDefPtr def,
                               virCapsPtr caps ATTRIBUTE_UNUSED)
@@ -3316,6 +3355,9 @@ virDomainDefPostParseInternal(virDomainDefPtr def,
         }
     }
 
+    /* clean up possibly duplicated metadata entries */
+    virDomainDefRemoveDuplicateMetadata(def);
+
     return 0;
 }
 

tests/qemuxml2argvdata/qemuxml2argv-metadata-duplicate.xml

+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219100</memory>
+  <currentMemory unit='KiB'>219100</currentMemory>
+  <vcpu placement='static' cpuset='1-4,8-20,525'>1</vcpu>
+  <os>
+    <type arch='i686' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu</emulator>
+    <disk type='block' device='disk'>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
+  </devices>
+  <!-- intentional mis-indentation -->
+  <metadata>
+      <app1:foo xmlns:app1="http://foo.org/">fooish</app1:foo>
+      <app3:foo xmlns:app3="http://foo.org/">fooish</app3:foo>
+      <app1:foo xmlns:app1="http://foo.org/">fooish</app1:foo>
+   <app2:bar xmlns:app2="http://bar.com/" maman="baz">barish</app2:bar>
+      <app1:foo xmlns:app1="http://foo.org/">fooish</app1:foo>
+   <app2:bar xmlns:app2="http://bar.com/" maman="baz">barish</app2:bar>
+  </metadata>
+</domain>

tests/qemuxml2xmloutdata/qemuxml2xmlout-metadata-duplicate.xml

+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <metadata>
+    <app1:foo xmlns:app1="http://foo.org/">fooish</app1:foo>
+    <app2:bar xmlns:app2="http://bar.com/" maman="baz">barish</app2:bar>
+  </metadata>
+  <memory unit='KiB'>219100</memory>
+  <currentMemory unit='KiB'>219100</currentMemory>
+  <vcpu placement='static' cpuset='1-4,8-20,525'>1</vcpu>
+  <os>
+    <type arch='i686' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu</emulator>
+    <disk type='block' device='disk'>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <controller type='ide' index='0'/>
+    <controller type='usb' index='0'/>
+    <controller type='pci' index='0' model='pci-root'/>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>

tests/qemuxml2xmltest.c

@@ -367,6 +367,7 @@ mymain(void)
     DO_TEST_DIFFERENT("usb-ich9-ehci-addr");
 
     DO_TEST_DIFFERENT("metadata");
+    DO_TEST_DIFFERENT("metadata-duplicate");
 
     DO_TEST("tpm-passthrough");
     DO_TEST("pci-bridge");