Fix assertions when ImageWallpaper is not default

This is a partial cherry-pick (see "Merged-In").

After a call to WallpaperManager#clear, don't assert that
getWallpaperInfo() returns null; instead, assert that getWallpaperInfo()
returns either null or returns a WallpaperInfo object for the default wallpaper

Bug: 307898569
Test: treehugger (check results for WallpaperManagerTest)
Change-Id: I764c014d4c2e4c1bd9cd6bbf81514019c3028499
Merged-In: Id4d65a5a808ee246a4e851e8212eb0207404f6e3

Author: Aurélien Pomini

tests/app/WallpaperTest/src/android/app/cts/wallpapers/WallpaperManagerTest.java

@@ -46,6 +46,7 @@
 
 import android.app.Activity;
 import android.app.WallpaperColors;
+import android.app.WallpaperInfo;
 import android.app.WallpaperManager;
 import android.content.BroadcastReceiver;
 import android.content.ComponentName;
@@ -117,6 +118,11 @@ public class WallpaperManagerTest {
     private BroadcastReceiver mBroadcastReceiver;
     private CountDownLatch mCountDownLatch;
     private boolean mEnableWcg;
+
+    // WallpaperInfo object for the built-in default wallpaper of the device.
+    // Always null if the device uses ImageWallpaper by default.
+    private WallpaperInfo mDefaultWallpaperInfo;
+
     private static final WindowManagerStateHelper sWindowManagerStateHelper =
             new WindowManagerStateHelper();
 
@@ -157,6 +163,9 @@ public void onReceive(Context context, Intent intent) {
                 new IntentFilter(Intent.ACTION_WALLPAPER_CHANGED));
         mEnableWcg = mWallpaperManager.shouldEnableWideColorGamut();
         mWallpaperManager.clear(FLAG_SYSTEM | FLAG_LOCK);
+        if (mDefaultWallpaperInfo == null) {
+            mDefaultWallpaperInfo = mWallpaperManager.getWallpaperInfo(FLAG_SYSTEM);
+        }
 
         assertWithMessage("Home screen wallpaper must be set after setUp()").that(
                 mWallpaperManager.getWallpaperId(FLAG_SYSTEM)).isAtLeast(0);
@@ -597,8 +606,8 @@ public void setWallpaperComponent_default_multiEngine_lockScreenUnset_behavesLik
 
     @Test
     public void setStaticWallpaper_doesNotSetWallpaperInfo() throws IOException {
-        assertThat(mWallpaperManager.getWallpaperInfo(FLAG_SYSTEM)).isNull();
-        assertThat(mWallpaperManager.getWallpaperInfo(FLAG_LOCK)).isNull();
+        assertNullOrDefaultWallpaper(FLAG_SYSTEM);
+        assertNullOrDefaultWallpaper(FLAG_LOCK);
 
         mWallpaperManager.setResource(R.drawable.icon_red, FLAG_SYSTEM);
         mWallpaperManager.setResource(R.drawable.icon_green, FLAG_LOCK);
@@ -609,17 +618,16 @@ public void setStaticWallpaper_doesNotSetWallpaperInfo() throws IOException {
 
     @Test
     public void setLiveWallpaper_homeScreen_setsHomeWallpaperInfo() {
-        assertThat(mWallpaperManager.getWallpaperInfo(FLAG_SYSTEM)).isNull();
-        assertThat(mWallpaperManager.getWallpaperInfo(FLAG_LOCK)).isNull();
+        assertNullOrDefaultWallpaper(FLAG_SYSTEM);
+        assertNullOrDefaultWallpaper(FLAG_LOCK);
 
         runWithShellPermissionIdentity(() -> {
             setWallpaperComponentAndWait(DEFAULT_COMPONENT_NAME, FLAG_SYSTEM);
         });
 
         assertWithMessage("Home screen").that(
                 mWallpaperManager.getWallpaperInfo(FLAG_SYSTEM)).isNotNull();
-        assertWithMessage("Lock screen").that(
-                mWallpaperManager.getWallpaperInfo(FLAG_LOCK)).isNull();
+        assertNullOrDefaultWallpaper(FLAG_LOCK);
     }
 
     @Test
@@ -641,15 +649,14 @@ public void setLiveWallpaper_lockScreen_singleEngine_setsHomeWallpaperInfo() {
     @Test
     public void setLiveWallpaper_lockScreen_multiEngine_setsLockWallpaperInfo() {
         assumeTrue(mWallpaperManager.isLockscreenLiveWallpaperEnabled());
-        assertThat(mWallpaperManager.getWallpaperInfo(FLAG_SYSTEM)).isNull();
-        assertThat(mWallpaperManager.getWallpaperInfo(FLAG_LOCK)).isNull();
+        assertNullOrDefaultWallpaper(FLAG_SYSTEM);
+        assertNullOrDefaultWallpaper(FLAG_LOCK);
 
         runWithShellPermissionIdentity(() -> {
             setWallpaperComponentAndWait(DEFAULT_COMPONENT_NAME, FLAG_LOCK);
         });
 
-        assertWithMessage("Home screen").that(
-                mWallpaperManager.getWallpaperInfo(FLAG_SYSTEM)).isNull();
+        assertNullOrDefaultWallpaper(FLAG_SYSTEM);
         assertWithMessage("Lock screen").that(
                 mWallpaperManager.getWallpaperInfo(FLAG_LOCK)).isNotNull();
     }
@@ -1696,6 +1703,13 @@ private void ensureCleanState(int flags) {
         }
     }
 
+    private void assertNullOrDefaultWallpaper(int which) {
+        WallpaperInfo wallpaperInfo = mWallpaperManager.getWallpaperInfo(which);
+        if (mDefaultWallpaperInfo == null) assertThat(wallpaperInfo).isNull();
+        if (wallpaperInfo == null) return;
+        assertThat(wallpaperInfo.getComponent()).isEqualTo(mDefaultWallpaperInfo.getComponent());
+    }
+
     private void setWallpaperComponentAndWait(ComponentName component, int which) {
         mWallpaperManager.setWallpaperComponentWithFlags(component, which);
         try {