commit 594b8b996c83724d6b1c73641daf277307afe5f7
Author: Jim Fehlig <jfehlig@suse.com>
Date:   Fri Mar 16 15:29:48 2018 -0600

    libxl: convert DefineXMLFlags to use begin/end API pattern
    
    Similar to other uses of virDomainObjListAdd, on success add a ref to the
    virDomainObj so that virDomainObjEndAPI can be called as usual.
    
    Signed-off-by: Jim Fehlig <jfehlig@suse.com>
    Reviewed-by: John Ferlan <jferlan@redhat.com>

Index: libvirt-4.1.0/src/libxl/libxl_driver.c
===================================================================
--- libvirt-4.1.0.orig/src/libxl/libxl_driver.c
+++ libvirt-4.1.0/src/libxl/libxl_driver.c
@@ -2794,6 +2794,7 @@ libxlDomainDefineXMLFlags(virConnectPtr
                                    &oldDef)))
         goto cleanup;
 
+    virObjectRef(vm);
     def = NULL;
     vm->persistent = 1;
 
@@ -2801,7 +2802,7 @@ libxlDomainDefineXMLFlags(virConnectPtr
                             cfg->caps,
                             vm->newDef ? vm->newDef : vm->def) < 0) {
         virDomainObjListRemove(driver->domains, vm);
-        vm = NULL;
+        virObjectLock(vm);
         goto cleanup;
     }
 
@@ -2815,8 +2816,7 @@ libxlDomainDefineXMLFlags(virConnectPtr
  cleanup:
     virDomainDefFree(def);
     virDomainDefFree(oldDef);
-    if (vm)
-        virObjectUnlock(vm);
+    virDomainObjEndAPI(&vm);
     if (event)
         libxlDomainEventQueue(driver, event);
     virObjectUnref(cfg);