snapshot: implement LIST_LEAVES flag in qemu

With the recent refactoring of qemu snapshot relationships, it
is now trivial to filter on leaves.

* src/conf/domain_conf.c (virDomainSnapshotObjListCount)
(virDomainSnapshotObjListCopyNames): Handle new flag.
* src/qemu/qemu_driver.c (qemuDomainSnapshotListNames)
(qemuDomainSnapshotNum, qemuDomainSnapshotListChildrenNames)
(qemuDomainSnapshotNumChildren): Pass new flag through.

src/conf/domain_conf.c

@@ -12170,7 +12170,9 @@ static void virDomainSnapshotObjListCopyNames(void *payload,
 
     if (data->oom)
         return;
-    if ((data->flags & VIR_DOMAIN_SNAPSHOT_LIST_ROOTS) && obj->def->parent)
+    /* LIST_ROOTS/LIST_DESCENDANTS was handled by caller,
+     * LIST_METADATA is a no-op if we get this far.  */
+    if ((data->flags & VIR_DOMAIN_SNAPSHOT_LIST_LEAVES) && obj->nchildren)
         return;
 
     if (data->numnames < data->maxnames) {
@@ -12255,7 +12257,9 @@ static void virDomainSnapshotObjListCount(void *payload,
     virDomainSnapshotObjPtr obj = payload;
     struct virDomainSnapshotNumData *data = opaque;
 
-    if ((data->flags & VIR_DOMAIN_SNAPSHOT_LIST_ROOTS) && obj->def->parent)
+    /* LIST_ROOTS/LIST_DESCENDANTS was handled by caller,
+     * LIST_METADATA is a no-op if we get this far.  */
+    if ((data->flags & VIR_DOMAIN_SNAPSHOT_LIST_LEAVES) && obj->nchildren)
         return;
     data->count++;
 }

src/qemu/qemu_driver.c

@@ -9415,7 +9415,8 @@ static int qemuDomainSnapshotListNames(virDomainPtr domain, char **names,
     int n = -1;
 
     virCheckFlags(VIR_DOMAIN_SNAPSHOT_LIST_ROOTS |
-                  VIR_DOMAIN_SNAPSHOT_LIST_METADATA, -1);
+                  VIR_DOMAIN_SNAPSHOT_LIST_METADATA |
+                  VIR_DOMAIN_SNAPSHOT_LIST_LEAVES, -1);
 
     qemuDriverLock(driver);
     vm = virDomainFindByUUID(&driver->domains, domain->uuid);
@@ -9445,7 +9446,8 @@ static int qemuDomainSnapshotNum(virDomainPtr domain,
     int n = -1;
 
     virCheckFlags(VIR_DOMAIN_SNAPSHOT_LIST_ROOTS |
-                  VIR_DOMAIN_SNAPSHOT_LIST_METADATA, -1);
+                  VIR_DOMAIN_SNAPSHOT_LIST_METADATA |
+                  VIR_DOMAIN_SNAPSHOT_LIST_LEAVES, -1);
 
     qemuDriverLock(driver);
     vm = virDomainFindByUUID(&driver->domains, domain->uuid);
@@ -9482,7 +9484,8 @@ qemuDomainSnapshotListChildrenNames(virDomainSnapshotPtr snapshot,
     int n = -1;
 
     virCheckFlags(VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS |
-                  VIR_DOMAIN_SNAPSHOT_LIST_METADATA, -1);
+                  VIR_DOMAIN_SNAPSHOT_LIST_METADATA |
+                  VIR_DOMAIN_SNAPSHOT_LIST_LEAVES, -1);
 
     qemuDriverLock(driver);
     vm = virDomainFindByUUID(&driver->domains, snapshot->domain->uuid);
@@ -9521,7 +9524,8 @@ qemuDomainSnapshotNumChildren(virDomainSnapshotPtr snapshot,
     int n = -1;
 
     virCheckFlags(VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS |
-                  VIR_DOMAIN_SNAPSHOT_LIST_METADATA, -1);
+                  VIR_DOMAIN_SNAPSHOT_LIST_METADATA |
+                  VIR_DOMAIN_SNAPSHOT_LIST_LEAVES, -1);
 
     qemuDriverLock(driver);
     vm = virDomainFindByUUID(&driver->domains, snapshot->domain->uuid);