Properly merge flags when merging transactions

Test: atest SurfaceFlinger_test

Change-Id: Ib1446c5afe00fd2588f7682f33cbbc6d6eb6a1ea

2 files changed, 27 insertions, 2 deletions

diff --git a/libs/gui/LayerState.cpp b/libs/gui/LayerState.cpp
index 6066421faf..aa07cbe0ab 100644
--- a/libs/gui/LayerState.cpp
+++ b/libs/gui/LayerState.cpp
@@ -267,8 +267,9 @@ void layer_state_t::merge(const layer_state_t& other) {
     }
     if (other.what & eFlagsChanged) {
         what |= eFlagsChanged;
-        flags = other.flags;
-        mask = other.mask;
+        flags &= ~other.mask;
+        flags |= (other.flags & other.mask);
+        mask |= other.mask;
     }
     if (other.what & eLayerStackChanged) {
         what |= eLayerStackChanged;
diff --git a/services/surfaceflinger/tests/Transaction_test.cpp b/services/surfaceflinger/tests/Transaction_test.cpp
index d5f65348d8..aed7b40872 100644
--- a/services/surfaceflinger/tests/Transaction_test.cpp
+++ b/services/surfaceflinger/tests/Transaction_test.cpp
@@ -4427,6 +4427,30 @@ TEST_F(LayerUpdateTest, MergingTransactions) {
     }
 }
 
+TEST_F(LayerUpdateTest, MergingTransactionFlags) {
+    Transaction().hide(mFGSurfaceControl).apply();
+    std::unique_ptr<ScreenCapture> sc;
+    {
+        SCOPED_TRACE("before merge");
+        ScreenCapture::captureScreen(&sc);
+        sc->expectBGColor(0, 12);
+        sc->expectBGColor(75, 75);
+        sc->expectBGColor(145, 145);
+    }
+
+    Transaction t1, t2;
+    t1.show(mFGSurfaceControl);
+    t2.setFlags(mFGSurfaceControl, 0 /* flags */, layer_state_t::eLayerSecure /* mask */);
+    t1.merge(std::move(t2));
+    t1.apply();
+
+    {
+        SCOPED_TRACE("after merge");
+        ScreenCapture::captureScreen(&sc);
+        sc->expectFGColor(75, 75);
+    }
+}
+
 class ChildLayerTest : public LayerUpdateTest {
 protected:
     void SetUp() override {