From 3442aa04a6dcced41f39882a9a9865f841540763 Mon Sep 17 00:00:00 2001
From: Lee Shombert <shombert@google.com>
Date: Wed, 12 May 2021 08:26:39 -0700
Subject: [PATCH] Fix ClassCastException in WatchedIntentResolver

Bug: 187691893

IntentResolver.sortResults() is a generic method that assumes its
argument is a List<IntentFilter>, although this is not explicit in the
data types.  The assumption fails in WatchedIntentResolver, which is
actually holding List<WatchedIntentFilter>.

The change follows the same path as server/firewall/IntentFirewall:
sortResults() is overridden in WatchedIntentResolver to accept the
proper type.  While we are at it, we force the class parameters in
WatchedIntentResolver to be WatchedIntentFilter (because that is
always true).  This means no casting is required to support
sortResults().

Finally, WatchedIntentResolver is moved into the server.pm package,
where it is actually used.  Should the need arise, it can be elevated
back to the server package.

Test: atest
 * CtsContentTestCases:IntentFilterTest
 * CtsDynamicMimeHostTestCases
 * FrameworksServicesTests:AppsFilterTest

Change-Id: Id1546c6711f95e0970c018b0e54cad7f3a8ac4b7
---
 .../server/pm/CrossProfileIntentResolver.java |  1 -
 .../pm/PersistentPreferredIntentResolver.java |  1 -
 .../server/pm/PreferredIntentResolver.java    |  1 -
 .../{ => pm}/WatchedIntentResolver.java       | 23 +++++++++++++++----
 4 files changed, 18 insertions(+), 8 deletions(-)
 rename services/core/java/com/android/server/{ => pm}/WatchedIntentResolver.java (82%)

diff --git a/services/core/java/com/android/server/pm/CrossProfileIntentResolver.java b/services/core/java/com/android/server/pm/CrossProfileIntentResolver.java
index 7927538603582..9ea16d322c3c0 100644
--- a/services/core/java/com/android/server/pm/CrossProfileIntentResolver.java
+++ b/services/core/java/com/android/server/pm/CrossProfileIntentResolver.java
@@ -19,7 +19,6 @@ package com.android.server.pm;
 import android.annotation.NonNull;
 import android.content.IntentFilter;
 
-import com.android.server.WatchedIntentResolver;
 import com.android.server.utils.Snappable;
 import com.android.server.utils.SnapshotCache;
 
diff --git a/services/core/java/com/android/server/pm/PersistentPreferredIntentResolver.java b/services/core/java/com/android/server/pm/PersistentPreferredIntentResolver.java
index bfddaea0dd756..bc65c3a7e20c0 100644
--- a/services/core/java/com/android/server/pm/PersistentPreferredIntentResolver.java
+++ b/services/core/java/com/android/server/pm/PersistentPreferredIntentResolver.java
@@ -19,7 +19,6 @@ package com.android.server.pm;
 import android.annotation.NonNull;
 import android.content.IntentFilter;
 
-import com.android.server.WatchedIntentResolver;
 import com.android.server.utils.Snappable;
 import com.android.server.utils.SnapshotCache;
 
diff --git a/services/core/java/com/android/server/pm/PreferredIntentResolver.java b/services/core/java/com/android/server/pm/PreferredIntentResolver.java
index 0aca6eec25fcc..fc7680bad9d4e 100644
--- a/services/core/java/com/android/server/pm/PreferredIntentResolver.java
+++ b/services/core/java/com/android/server/pm/PreferredIntentResolver.java
@@ -19,7 +19,6 @@ package com.android.server.pm;
 import android.annotation.NonNull;
 import android.content.IntentFilter;
 
-import com.android.server.WatchedIntentResolver;
 import com.android.server.utils.Snappable;
 import com.android.server.utils.SnapshotCache;
 
diff --git a/services/core/java/com/android/server/WatchedIntentResolver.java b/services/core/java/com/android/server/pm/WatchedIntentResolver.java
similarity index 82%
rename from services/core/java/com/android/server/WatchedIntentResolver.java
rename to services/core/java/com/android/server/pm/WatchedIntentResolver.java
index 0831c36d2bf6a..1c3d884e3a988 100644
--- a/services/core/java/com/android/server/WatchedIntentResolver.java
+++ b/services/core/java/com/android/server/pm/WatchedIntentResolver.java
@@ -14,18 +14,20 @@
  * limitations under the License.
  */
 
-package com.android.server;
+package com.android.server.pm;
 
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 
-import com.android.server.pm.WatchedIntentFilter;
+import com.android.server.IntentResolver;
 import com.android.server.utils.Snappable;
 import com.android.server.utils.Watchable;
 import com.android.server.utils.WatchableImpl;
 import com.android.server.utils.Watcher;
 
 import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
 import java.util.List;
 
 /**
@@ -34,7 +36,8 @@ import java.util.List;
  * @param <R> The resolver type.
  * {@hide}
  */
-public abstract class WatchedIntentResolver<F extends Watchable, R extends Object>
+public abstract class WatchedIntentResolver<F extends WatchedIntentFilter,
+                                            R extends WatchedIntentFilter>
         extends IntentResolver<F, R>
         implements Watchable, Snappable {
 
@@ -116,11 +119,21 @@ public abstract class WatchedIntentResolver<F extends Watchable, R extends Objec
         onChanged();
     }
 
+    // Sorts a List of IntentFilter objects into descending priority order.
+    @SuppressWarnings("rawtypes")
+    private static final Comparator<WatchedIntentFilter> sResolvePrioritySorter =
+            new Comparator<>() {
+        public int compare(WatchedIntentFilter o1, WatchedIntentFilter o2) {
+            final int q1 = o1.getPriority();
+            final int q2 = o2.getPriority();
+            return (q1 > q2) ? -1 : ((q1 < q2) ? 1 : 0);
+        }
+    };
+
     @Override
     @SuppressWarnings("unchecked")
     protected void sortResults(List<R> results) {
-        super.sortResults(results);
-        onChanged();
+        Collections.sort(results, sResolvePrioritySorter);
     }
 
     /**