Prevent and log invalid cache entries.

Bug: 25413518
Change-Id: Id0a7384eccd25ba766feb0c568b4c16db2b6f6c8

packages/SystemUI/src/com/android/systemui/recents/model/RecentsTaskLoader.java

@@ -560,6 +560,11 @@ public class RecentsTaskLoader {
         ActivityInfo activityInfo = mActivityInfoCache.get(cn);
         if (activityInfo == null) {
             activityInfo = ssp.getActivityInfo(cn, taskKey.userId);
+            if (cn == null || activityInfo == null) {
+                Log.e(TAG, "Unexpected null component name or activity info: " + cn + ", " +
+                        activityInfo);
+                return null;
+            }
             mActivityInfoCache.put(cn, activityInfo);
         }
         return activityInfo;

packages/SystemUI/src/com/android/systemui/recents/model/TaskKeyLruCache.java

@@ -16,6 +16,7 @@
 
 package com.android.systemui.recents.model;
 
+import android.util.Log;
 import android.util.LruCache;
 import android.util.SparseArray;
 
@@ -29,6 +30,8 @@ import android.util.SparseArray;
  */
 public class TaskKeyLruCache<V> {
 
+    private static final String TAG = "TaskKeyLruCache";
+
     private final SparseArray<Task.TaskKey> mKeys = new SparseArray<>();
     private final LruCache<Integer, V> mCache;
 
@@ -71,6 +74,10 @@ public class TaskKeyLruCache<V> {
 
     /** Puts an entry in the cache for a specific key. */
     final void put(Task.TaskKey key, V value) {
+        if (key == null || value == null) {
+            Log.e(TAG, "Unexpected null key or value: " + key + ", " + value);
+            return;
+        }
         mKeys.put(key.id, key);
         mCache.put(key.id, value);
     }