TaskStackBuilder and intents without an explicit target

When Activity#getParentActivityIntent() returns an Intent without an
explicit target, resolve it in order to determine a correct parent
stack.

Bug 7223318

Change-Id: I3e88129f1e538cc3d932d6b4f735a5bec54bb4ad

Author: adamp

core/java/android/app/TaskStackBuilder.java

@@ -128,7 +128,11 @@ public TaskStackBuilder addParentStack(Activity sourceActivity) {
         if (parent != null) {
             // We have the actual parent intent, build the rest from static metadata
             // then add the direct parent intent to the end.
-            addParentStack(parent.getComponent());
+            ComponentName target = parent.getComponent();
+            if (target == null) {
+                target = parent.resolveActivity(mSourceContext.getPackageManager());
+            }
+            addParentStack(target);
             addNextIntent(parent);
         }
         return this;