[PATCH 16/17] virDomainSnapshotAssignDef: Clear second argument when it is consumed

[Peter Krempa <pkrempa@xxxxxxxxxx>]

Rather than callers second-guessing when the snapshot definition is
assigned turn it into a double pointer and clear it on success.

Fix callers to work with the new semantics.

Signed-off-by: Peter Krempa <pkrempa@xxxxxxxxxx>
---
 src/conf/virdomainsnapshotobjlist.c | 10 ++++++++--
 src/conf/virdomainsnapshotobjlist.h |  2 +-
 src/qemu/qemu_driver.c              |  4 +---
 src/qemu/qemu_snapshot.c            |  6 ++----
 src/test/test_driver.c              | 12 ++++--------
 src/vz/vz_sdk.c                     |  3 +--
 6 files changed, 17 insertions(+), 20 deletions(-)

diff --git a/src/conf/virdomainsnapshotobjlist.c b/src/conf/virdomainsnapshotobjlist.c
index 0ccdf31ae0..6b074d5994 100644
--- a/src/conf/virdomainsnapshotobjlist.c
+++ b/src/conf/virdomainsnapshotobjlist.c
@@ -42,9 +42,15 @@ struct _virDomainSnapshotObjList {

 virDomainMomentObj *
 virDomainSnapshotAssignDef(virDomainSnapshotObjList *snapshots,
-                           virDomainSnapshotDef *def)
+                           virDomainSnapshotDef **snapdefptr)
 {
-    return virDomainMomentAssignDef(snapshots->base, &def->parent);
+    virDomainSnapshotDef *snapdef = *snapdefptr;
+    virDomainMomentObj *ret = virDomainMomentAssignDef(snapshots->base, &snapdef->parent);
+
+    if (ret)
+        *snapdefptr = NULL;
+
+    return ret;
 }


diff --git a/src/conf/virdomainsnapshotobjlist.h b/src/conf/virdomainsnapshotobjlist.h
index eebeb9f5a3..bdbc17f6d5 100644
--- a/src/conf/virdomainsnapshotobjlist.h
+++ b/src/conf/virdomainsnapshotobjlist.h
@@ -30,7 +30,7 @@ virDomainSnapshotObjList *virDomainSnapshotObjListNew(void);
 void virDomainSnapshotObjListFree(virDomainSnapshotObjList *snapshots);

 virDomainMomentObj *virDomainSnapshotAssignDef(virDomainSnapshotObjList *snapshots,
-                                               virDomainSnapshotDef *def);
+                                               virDomainSnapshotDef **snapdefptr);

 int virDomainSnapshotObjListGetNames(virDomainSnapshotObjList *snapshots,
                                      virDomainMomentObj *from,
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index b3588f9478..e150b86cef 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -396,9 +396,7 @@ qemuDomainSnapshotLoad(virDomainObj *vm,
             continue;
         }

-        snap = virDomainSnapshotAssignDef(vm->snapshots, snapdef);
-        if (snap)
-            snapdef = NULL;
+        snap = virDomainSnapshotAssignDef(vm->snapshots, &snapdef);
         if (cur && snap) {
             if (current)
                 virReportError(VIR_ERR_INTERNAL_ERROR,
diff --git a/src/qemu/qemu_snapshot.c b/src/qemu/qemu_snapshot.c
index c5379d583e..3e35ff5463 100644
--- a/src/qemu/qemu_snapshot.c
+++ b/src/qemu/qemu_snapshot.c
@@ -1721,9 +1721,8 @@ qemuSnapshotRedefine(virDomainObj *vm,
         return NULL;

     if (!snap) {
-        if (!(snap = virDomainSnapshotAssignDef(vm->snapshots, snapdef)))
+        if (!(snap = virDomainSnapshotAssignDef(vm->snapshots, &snapdef)))
             return NULL;
-        snapdef = NULL;
     }
     /* XXX Should we validate that the redefined snapshot even
      * makes sense, such as checking that qemu-img recognizes the
@@ -1772,9 +1771,8 @@ qemuSnapshotCreate(virDomainObj *vm,
         snap->def = &snapdef->parent;
         snapdef = NULL;
     } else {
-        if (!(snap = virDomainSnapshotAssignDef(vm->snapshots, snapdef)))
+        if (!(snap = virDomainSnapshotAssignDef(vm->snapshots, &snapdef)))
             return NULL;
-        snapdef = NULL;

         if ((current = virDomainSnapshotGetCurrent(vm->snapshots))) {
             snap->def->parent_name = g_strdup(current->def->name);
diff --git a/src/test/test_driver.c b/src/test/test_driver.c
index e772b2be2b..14617d4f0d 100644
--- a/src/test/test_driver.c
+++ b/src/test/test_driver.c
@@ -968,7 +968,7 @@ testParseDomainSnapshots(testDriver *privconn,

     for (i = 0; i < nsdata->num_snap_nodes; i++) {
         virDomainMomentObj *snap;
-        virDomainSnapshotDef *def;
+        g_autoptr(virDomainSnapshotDef) def = NULL;
         xmlNodePtr node = testParseXMLDocFromFile(nodes[i], file,
                                                   "domainsnapshot");
         if (!node)
@@ -984,10 +984,8 @@ testParseDomainSnapshots(testDriver *privconn,
         if (!def)
             return -1;

-        if (!(snap = virDomainSnapshotAssignDef(domobj->snapshots, def))) {
-            virObjectUnref(def);
+        if (!(snap = virDomainSnapshotAssignDef(domobj->snapshots, &def)))
             return -1;
-        }

         if (cur) {
             if (virDomainSnapshotGetCurrent(domobj->snapshots)) {
@@ -8755,9 +8753,8 @@ testDomainSnapshotRedefine(virDomainObj *vm,
         return NULL;

     if (!snap) {
-        if (!(snap = virDomainSnapshotAssignDef(vm->snapshots, snapdef)))
+        if (!(snap = virDomainSnapshotAssignDef(vm->snapshots, &snapdef)))
             return NULL;
-        snapdef = NULL;
     }

     *snapout = snap;
@@ -8846,9 +8843,8 @@ testDomainSnapshotCreateXML(virDomainPtr domain,
     if (testDomainSnapshotAlignDisks(vm, def, flags) < 0)
         goto cleanup;

-    if (!(snap = virDomainSnapshotAssignDef(vm->snapshots, def)))
+    if (!(snap = virDomainSnapshotAssignDef(vm->snapshots, &def)))
         goto cleanup;
-    def = NULL;

     snap->def->parent_name = g_strdup(virDomainSnapshotGetCurrentName(vm->snapshots));

diff --git a/src/vz/vz_sdk.c b/src/vz/vz_sdk.c
index 5ed33902fd..94c6cd5c7a 100644
--- a/src/vz/vz_sdk.c
+++ b/src/vz/vz_sdk.c
@@ -4661,9 +4661,8 @@ prlsdkParseSnapshotTree(const char *treexml)
         }
         VIR_FREE(xmlstr);

-        if (!(snapshot = virDomainSnapshotAssignDef(snapshots, def)))
+        if (!(snapshot = virDomainSnapshotAssignDef(snapshots, &def)))
             goto cleanup;
-        def = NULL;

         xmlstr = virXPathString("string(./@current)", ctxt);
         if (xmlstr && STREQ("yes", xmlstr)) {
-- 
2.31.1