From f5b13525100ea66b112dcd01abc00c485e1082c8 Mon Sep 17 00:00:00 2001
From: Ming-Shin Lu <lumark@google.com>
Date: Thu, 17 Feb 2022 21:47:33 +0800
Subject: [PATCH] Fix a redundant assignRelativeLayerForIme case

Somehow in FlickerTest#CloseAppBackButtonTest
with enabling shell-transition flag will see a weird case is that first
launcher be set relativeZ to above IME container during closing the IME
actiivty, which is understandable since home activity is not IME target
during transient launch,

but soonly in assignRelativeLayerForIme will
set IME container's relativeZ to be above launcher after recents
animation finish.

This action will confuse SurfaceFlinger side while invoking
Layer::isHiddenByPolicy() to traverse all layers using relativeZ and
cause stack-overflow due to circulated relativeZ relationship in between
launcher and IME container.

As we don't need to set relative layer if the IME target in non-multi-window
mode is the activity main window since updateImeParent will ensure the IME
surface be attached on the fullscreen activity.

Add a check in assignRelativeLayerForIme to not set RelativeZ if
the IME target is the full screen activity, to break out circulated
RelativeZ in between ImeContainer & Launcher window layer.

Fix: 219774897
Test: atest ZOrderingTest
Test: atest FlickerTests#CloseAppBackButtonTest --iterations 20

Change-Id: I5abff1980328dc47ee193429a76a5d39a8625899
---
 services/core/java/com/android/server/wm/DisplayContent.java  | 4 ++++
 .../wmtests/src/com/android/server/wm/ZOrderingTests.java     | 3 ++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index 4c5c7054e9a0a..bd9f130e16189 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -5009,6 +5009,10 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
             final boolean canImeTargetSetRelativeLayer = imeTarget.getSurfaceControl() != null
                     && imeTarget.mToken == imeControlTargetToken
                     && !imeTarget.inMultiWindowMode()
+                    // We don't need to set relative layer if the IME target in non-multi-window
+                    // mode is the activity main window since updateImeParent will ensure the IME
+                    // surface be attached on the fullscreen activity.
+                    && imeTarget.mAttrs.type != TYPE_BASE_APPLICATION
                     && imeTarget.mToken.getActivity(app -> app.isAnimating(TRANSITION | PARENTS,
                             ANIMATION_TYPE_ALL & ~ANIMATION_TYPE_RECENTS)) == null;
             if (canImeTargetSetRelativeLayer) {
diff --git a/services/tests/wmtests/src/com/android/server/wm/ZOrderingTests.java b/services/tests/wmtests/src/com/android/server/wm/ZOrderingTests.java
index 0f223ca037ee4..eea3f844b40ff 100644
--- a/services/tests/wmtests/src/com/android/server/wm/ZOrderingTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/ZOrderingTests.java
@@ -293,7 +293,8 @@ public class ZOrderingTests extends WindowTestsBase {
     public void testAssignWindowLayers_ForImeWithAppTargetAndAppAbove() {
         final WindowState appBelowImeTarget = createWindow("appBelowImeTarget");
         final WindowState imeAppTarget = createWindow("imeAppTarget");
-        final WindowState appAboveImeTarget = createWindow("appAboveImeTarget");
+        final WindowState appAboveImeTarget = createWindow(imeAppTarget, TYPE_APPLICATION,
+                "appAboveImeTarget");
 
         mDisplayContent.setImeLayeringTarget(imeAppTarget);
         mDisplayContent.setImeControlTarget(imeAppTarget);