From 0d5792e9822fb26a2e3c9fee67f46a02f2a84941 Mon Sep 17 00:00:00 2001
From: wilsonshih <wilsonshih@google.com>
Date: Thu, 4 Jul 2019 11:23:54 +0800
Subject: [PATCH] Clear the calling identity in isUsableDisplay.

The INTERNAL_SYSTEM_WINDOW permission is checked when
WindowManagerService#shouldShowSystemDecors is called, we should leave
this permission check because it is public method.
Clear the calling identity in WallpaperManagerService#isUsableDisplay
as this method should be used only internally.

Fix: 136447676
Test: atest VrDisplayTests MultiDisplaySystemDecorationTests
Change-Id: I97a93cdd0253933527010f97049694b59d5a4e2a
---
 .../server/wallpaper/WallpaperManagerService.java    | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/services/core/java/com/android/server/wallpaper/WallpaperManagerService.java b/services/core/java/com/android/server/wallpaper/WallpaperManagerService.java
index 9908b3657121b..b0f1e5d69be40 100644
--- a/services/core/java/com/android/server/wallpaper/WallpaperManagerService.java
+++ b/services/core/java/com/android/server/wallpaper/WallpaperManagerService.java
@@ -1172,8 +1172,16 @@ public class WallpaperManagerService extends IWallpaperManager.Stub
                 return false;
             }
             final int displayId = display.getDisplayId();
-            return displayId == DEFAULT_DISPLAY
-                    || mWindowManagerInternal.shouldShowSystemDecorOnDisplay(displayId);
+            if (displayId == DEFAULT_DISPLAY) {
+                return true;
+            }
+
+            final long ident = Binder.clearCallingIdentity();
+            try {
+                return mWindowManagerInternal.shouldShowSystemDecorOnDisplay(displayId);
+            } finally {
+                Binder.restoreCallingIdentity(ident);
+            }
         }
 
         void forEachDisplayConnector(Consumer<DisplayConnector> action) {