Avoid clearing transaction flags too early

Transaction flags were cleared in commitTransactions  before
checking if we needed to run the composite stage. This caused
us to miss some updates. In addition, display  color matrix is only
updated if the colorMatrixChanged is set so, if we miss an update
device would be in an invalid state until the next update.

Fixes: 300194609
Test: presubmit
Change-Id: Ie397d4c37af6b54ff8d59e1151ddee24811e2d13
diff --git a/services/surfaceflinger/tests/unittests/CommitTest.cpp b/services/surfaceflinger/tests/unittests/CommitTest.cpp
new file mode 100644
index 0000000..df53d19
--- /dev/null
+++ b/services/surfaceflinger/tests/unittests/CommitTest.cpp
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#undef LOG_TAG
+#define LOG_TAG "CommitTest"
+
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+#include <renderengine/mock/RenderEngine.h>
+#include "TestableSurfaceFlinger.h"
+
+namespace android {
+
+class CommitTest : public testing::Test {
+protected:
+    CommitTest() {
+        mFlinger.setupMockScheduler();
+        mFlinger.setupComposer(std::make_unique<Hwc2::mock::Composer>());
+        mFlinger.setupRenderEngine(std::unique_ptr<renderengine::RenderEngine>(mRenderEngine));
+    }
+    TestableSurfaceFlinger mFlinger;
+    renderengine::mock::RenderEngine* mRenderEngine = new renderengine::mock::RenderEngine();
+};
+
+namespace {
+
+TEST_F(CommitTest, noUpdatesDoesNotScheduleComposite) {
+    bool unused;
+    bool mustComposite = mFlinger.updateLayerSnapshots(VsyncId{1}, /*frameTimeNs=*/0,
+                                                       /*transactionsFlushed=*/0, unused);
+    EXPECT_FALSE(mustComposite);
+}
+
+// Ensure that we handle eTransactionNeeded correctly
+TEST_F(CommitTest, eTransactionNeededFlagSchedulesComposite) {
+    // update display level color matrix
+    mFlinger.setDaltonizerType(ColorBlindnessType::Deuteranomaly);
+    bool unused;
+    bool mustComposite = mFlinger.updateLayerSnapshots(VsyncId{1}, /*frameTimeNs=*/0,
+                                                       /*transactionsFlushed=*/0, unused);
+    EXPECT_TRUE(mustComposite);
+}
+
+} // namespace
+} // namespace android