TaskStackBuilder correctness fixes

* Don't mutate original intents when adding default flags.

* Add the relevant flags to the array returned by getIntents() such
  that it can be used directly in a call to startActivities or
  similar.

* Deep copy the component intents when building an intent array for
  getIntents()

* Clean up some internal code duplication

Change-Id: I71d3b7f30d4f7d8f1cce778d406ea0e513d382c5

Author: adamp

core/java/android/app/TaskStackBuilder.java

@@ -216,11 +216,7 @@ public void startActivities(Bundle options) {
                     "No intents added to TaskStackBuilder; cannot startActivities");
         }
 
-        Intent[] intents = mIntents.toArray(new Intent[mIntents.size()]);
-        intents[0].addFlags(Intent.FLAG_ACTIVITY_NEW_TASK |
-                Intent.FLAG_ACTIVITY_CLEAR_TASK |
-                Intent.FLAG_ACTIVITY_TASK_ON_HOME);
-        mSourceContext.startActivities(intents, options);
+        mSourceContext.startActivities(getIntents(), options);
     }
 
     /**
@@ -260,11 +256,8 @@ public PendingIntent getPendingIntent(int requestCode, int flags, Bundle options
                     "No intents added to TaskStackBuilder; cannot getPendingIntent");
         }
 
-        Intent[] intents = mIntents.toArray(new Intent[mIntents.size()]);
-        intents[0].addFlags(Intent.FLAG_ACTIVITY_NEW_TASK |
-                Intent.FLAG_ACTIVITY_CLEAR_TASK |
-                Intent.FLAG_ACTIVITY_TASK_ON_HOME);
-        return PendingIntent.getActivities(mSourceContext, requestCode, intents, flags, options);
+        return PendingIntent.getActivities(mSourceContext, requestCode, getIntents(),
+                flags, options);
     }
 
     /**
@@ -275,6 +268,15 @@ public PendingIntent getPendingIntent(int requestCode, int flags, Bundle options
      * @return An array containing the intents added to this builder.
      */
     public Intent[] getIntents() {
-        return mIntents.toArray(new Intent[mIntents.size()]);
+        Intent[] intents = new Intent[mIntents.size()];
+        if (intents.length == 0) return intents;
+
+        intents[0] = new Intent(mIntents.get(0)).addFlags(Intent.FLAG_ACTIVITY_NEW_TASK |
+                Intent.FLAG_ACTIVITY_CLEAR_TASK |
+                Intent.FLAG_ACTIVITY_TASK_ON_HOME);
+        for (int i = 1; i < intents.length; i++) {
+            intents[i] = new Intent(mIntents.get(i));
+        }
+        return intents;
     }
 }