snapshot: Add virDomainSnapshotDefNew

In preparation for making virDomainSnapshotDef a descendant of
virObject, it is time to fix all callers that allocate an object to
use virDomainSnapshotDefNew() instead of VIR_ALLOC().  Fortunately,
there aren't very many :)

Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>

src/conf/snapshot_conf.c

@@ -81,6 +81,15 @@ virDomainSnapshotDiskDefClear(virDomainSnapshotDiskDefPtr disk)
     disk->src = NULL;
 }
 
+virDomainSnapshotDefPtr
+virDomainSnapshotDefNew(void)
+{
+    virDomainSnapshotDefPtr def;
+
+    ignore_value(VIR_ALLOC(def));
+    return def;
+}
+
 void virDomainSnapshotDefFree(virDomainSnapshotDefPtr def)
 {
     size_t i;
@@ -205,8 +214,8 @@ virDomainSnapshotDefParse(xmlXPathContextPtr ctxt,
     bool offline = !!(flags & VIR_DOMAIN_SNAPSHOT_PARSE_OFFLINE);
     virSaveCookieCallbacksPtr saveCookie = virDomainXMLOptionGetSaveCookie(xmlopt);
 
-    if (VIR_ALLOC(def) < 0)
-        goto cleanup;
+    if (!(def = virDomainSnapshotDefNew()))
+        return NULL;
 
     def->parent.name = virXPathString("string(./name)", ctxt);
     if (def->parent.name == NULL) {

src/conf/snapshot_conf.h

@@ -114,6 +114,7 @@ virDomainSnapshotDefPtr virDomainSnapshotDefParseNode(xmlDocPtr xml,
                                                       virDomainXMLOptionPtr xmlopt,
                                                       bool *current,
                                                       unsigned int flags);
+virDomainSnapshotDefPtr virDomainSnapshotDefNew(void);
 void virDomainSnapshotDefFree(virDomainSnapshotDefPtr def);
 char *virDomainSnapshotDefFormat(const char *uuidstr,
                                  virDomainSnapshotDefPtr def,

src/libvirt_private.syms

@@ -894,6 +894,7 @@ virDomainSnapshotAlignDisks;
 virDomainSnapshotDefFormat;
 virDomainSnapshotDefFree;
 virDomainSnapshotDefIsExternal;
+virDomainSnapshotDefNew;
 virDomainSnapshotDefParseString;
 virDomainSnapshotFormatConvertXMLFlags;
 virDomainSnapshotIsExternal;

src/vbox/vbox_common.c

@@ -6220,7 +6220,8 @@ static char *vboxDomainSnapshotGetXMLDesc(virDomainSnapshotPtr snapshot,
     if (!(snap = vboxDomainSnapshotGet(data, dom, machine, snapshot->name)))
         goto cleanup;
 
-    if (VIR_ALLOC(def) < 0 || !(def->parent.dom = virDomainDefNew()))
+    if (!(def = virDomainSnapshotDefNew()) ||
+        !(def->parent.dom = virDomainDefNew()))
         goto cleanup;
     defdom = def->parent.dom;
     if (VIR_STRDUP(def->parent.name, snapshot->name) < 0)