qemu: backup: Return 'def' instead of 'obj' from qemuBackupBeginCollectIncrementalCheckpoints

The object itself has no extra value and it would make testing the code
harder. Refactor it to remove just the definition pointer.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

src/qemu/qemu_backup.c

@@ -174,7 +174,7 @@ qemuBackupDiskDataCleanup(virDomainObjPtr vm,
 static int
 qemuBackupDiskPrepareOneBitmaps(struct qemuBackupDiskData *dd,
                                 virJSONValuePtr actions,
-                                virDomainMomentObjPtr *incremental)
+                                virDomainMomentDefPtr *incremental)
 {
     g_autoptr(virJSONValue) mergebitmaps = NULL;
     g_autoptr(virJSONValue) mergebitmapsstore = NULL;
@@ -188,7 +188,7 @@ qemuBackupDiskPrepareOneBitmaps(struct qemuBackupDiskData *dd,
     while (*incremental) {
         if (qemuMonitorTransactionBitmapMergeSourceAddBitmap(mergebitmaps,
                                                              dd->domdisk->src->nodeformat,
-                                                             (*incremental)->def->name) < 0)
+                                                             (*incremental)->name) < 0)
             return -1;
 
         incremental++;
@@ -232,7 +232,7 @@ qemuBackupDiskPrepareDataOne(virDomainObjPtr vm,
                              virDomainBackupDiskDefPtr backupdisk,
                              struct qemuBackupDiskData *dd,
                              virJSONValuePtr actions,
-                             virDomainMomentObjPtr *incremental,
+                             virDomainMomentDefPtr *incremental,
                              virQEMUDriverConfigPtr cfg,
                              bool removeStore)
 {
@@ -323,7 +323,7 @@ qemuBackupDiskPrepareDataOnePull(virJSONValuePtr actions,
 static ssize_t
 qemuBackupDiskPrepareData(virDomainObjPtr vm,
                           virDomainBackupDefPtr def,
-                          virDomainMomentObjPtr *incremental,
+                          virDomainMomentDefPtr *incremental,
                           virJSONValuePtr actions,
                           virQEMUDriverConfigPtr cfg,
                           struct qemuBackupDiskData **rdd,
@@ -505,24 +505,27 @@ qemuBackupBeginPullExportDisks(virDomainObjPtr vm,
  * @vm: domain object
  * @incrFrom: name of checkpoint representing starting point of incremental backup
  *
- * Returns a NULL terminated list of pointers to checkpoints in chronological
- * order starting from the 'current' checkpoint until reaching @incrFrom.
+ * Returns a NULL terminated list of pointers to checkpoint definitions in
+ * chronological order starting from the 'current' checkpoint until reaching
+ * @incrFrom.
  */
-static virDomainMomentObjPtr *
+static virDomainMomentDefPtr *
 qemuBackupBeginCollectIncrementalCheckpoints(virDomainObjPtr vm,
                                              const char *incrFrom)
 {
     virDomainMomentObjPtr n = virDomainCheckpointGetCurrent(vm->checkpoints);
-    g_autofree virDomainMomentObjPtr *incr = NULL;
+    g_autofree virDomainMomentDefPtr *incr = NULL;
     size_t nincr = 0;
 
     while (n) {
-        if (VIR_APPEND_ELEMENT_COPY(incr, nincr, n) < 0)
+        virDomainMomentDefPtr def = n->def;
+
+        if (VIR_APPEND_ELEMENT_COPY(incr, nincr, def) < 0)
             return NULL;
 
-        if (STREQ(n->def->name, incrFrom)) {
-            virDomainMomentObjPtr terminator = NULL;
-            if (VIR_APPEND_ELEMENT_COPY(incr, nincr, terminator) < 0)
+        if (STREQ(def->name, incrFrom)) {
+            def = NULL;
+            if (VIR_APPEND_ELEMENT_COPY(incr, nincr, def) < 0)
                 return NULL;
 
             return g_steal_pointer(&incr);
@@ -648,7 +651,7 @@ qemuBackupBegin(virDomainObjPtr vm,
     bool pull = false;
     virDomainMomentObjPtr chk = NULL;
     g_autoptr(virDomainCheckpointDef) chkdef = NULL;
-    g_autofree virDomainMomentObjPtr *incremental = NULL;
+    g_autofree virDomainMomentDefPtr *incremental = NULL;
     g_autoptr(virJSONValue) actions = NULL;
     struct qemuBackupDiskData *dd = NULL;
     ssize_t ndd = 0;