commit 8b196599033619f430573aa12181b9f5bb260c42
author Marin Shalamanov <shalamanov@google.com> Mon Aug 09 16:24:42 2021 +0200
committer Marin Shalamanov <shalamanov@google.com> Tue Aug 10 12:00:02 2021 +0200
tree 6d64761978e9c35cdf87976c13aa12f80f059d7f
parent eb03b0507fbef9e2bd772bd8f8f3f66dbed6f2a8

HWComposer: Unset mPrimaryHwcDisplayId after disconnectDisplay

We should unset mPrimaryHwcDisplayId when disconnectDisplay()
is called for the primary display. This can happen during
display change and it will cause isHeadless() to be false.
This way SurfaceFlinger will call getPrimaryDisplayId()
which will crash.

Test: HWComposerTest
Test: libsurfaceflinger_unittest
Bug: 195900759
Change-Id: I3c00e3b864fef6f1b088ffae0539c1ad16b7492b

services/surfaceflinger/tests/unittests/HWComposerTest.cpp

diff --git a/services/surfaceflinger/tests/unittests/HWComposerTest.cpp b/services/surfaceflinger/tests/unittests/HWComposerTest.cpp
index 655baf8..7fda8b3 100644
--- a/services/surfaceflinger/tests/unittests/HWComposerTest.cpp
+++ b/services/surfaceflinger/tests/unittests/HWComposerTest.cpp
@@ -36,6 +36,7 @@
 #include "DisplayHardware/DisplayMode.h"
 #include "DisplayHardware/HWComposer.h"
 #include "DisplayHardware/Hal.h"
+#include "DisplayIdentificationTest.h"
 #include "mock/DisplayHardware/MockComposer.h"
 #include "mock/DisplayHardware/MockHWC2.h"
 
@@ -57,6 +58,29 @@
 using ::testing::SetArgPointee;
 using ::testing::StrictMock;
 
+TEST(HWComposerTest, isHeadless) {
+    Hwc2::mock::Composer* mHal = new StrictMock<Hwc2::mock::Composer>();
+    impl::HWComposer hwc{std::unique_ptr<Hwc2::Composer>(mHal)};
+    ASSERT_TRUE(hwc.isHeadless());
+
+    const hal::HWDisplayId hwcId = 1;
+
+    EXPECT_CALL(*mHal, getDisplayIdentificationData(_, _, _))
+            .WillOnce(DoAll(SetArgPointee<2>(getExternalEdid()),
+                            Return(hardware::graphics::composer::V2_1::Error::NONE)));
+
+    EXPECT_CALL(*mHal, setVsyncEnabled(_, _));
+    EXPECT_CALL(*mHal, setClientTargetSlotCount(_));
+
+    auto info = hwc.onHotplug(hwcId, hal::Connection::CONNECTED);
+    ASSERT_TRUE(info);
+    auto displayId = info->id;
+    ASSERT_FALSE(hwc.isHeadless());
+
+    hwc.disconnectDisplay(displayId);
+    ASSERT_TRUE(hwc.isHeadless());
+}
+
 struct MockHWC2ComposerCallback final : StrictMock<HWC2::ComposerCallback> {
     MOCK_METHOD2(onComposerHalHotplug, void(hal::HWDisplayId, hal::Connection));
     MOCK_METHOD1(onComposerHalRefresh, void(hal::HWDisplayId));