3 files changed, 21 insertions, 2 deletions

diff --git a/src/burn/engine/engine.cpp b/src/burn/engine/engine.cpp
index 413db69b..334ea23b 100644
--- a/src/burn/engine/engine.cpp
+++ b/src/burn/engine/engine.cpp
@@ -132,7 +132,7 @@ extern "C" HRESULT EngineRun(
 
     engineState.command.nCmdShow = nCmdShow;
 
-    if (BURN_MODE_ELEVATED != engineState.internalCommand.mode && BOOTSTRAPPER_DISPLAY_NONE < engineState.command.display && !engineState.command.hwndSplashScreen)
+    if (BURN_MODE_ELEVATED != engineState.internalCommand.mode && BOOTSTRAPPER_DISPLAY_NONE < engineState.command.display)
     {
         SplashScreenCreate(hInstance, NULL, &engineState.command.hwndSplashScreen);
     }
diff --git a/src/burn/engine/splashscreen.cpp b/src/burn/engine/splashscreen.cpp
index 7ba4e630..d8618feb 100644
--- a/src/burn/engine/splashscreen.cpp
+++ b/src/burn/engine/splashscreen.cpp
@@ -13,6 +13,7 @@ struct SPLASHSCREEN_INFO
     SIZE size;
     UINT nDpi;
     HWND hWnd;
+    HWND hwndPrevious;
 };
 
 struct SPLASHSCREEN_CONTEXT
@@ -258,6 +259,19 @@ static LRESULT CALLBACK WndProc(
     case WM_ERASEBKGND:
         OnEraseBkgnd(pSplashScreen, wParam);
         return 1;
+
+    case WM_ENTERIDLE:
+        lres = ::DefWindowProcW(hWnd, uMsg, wParam, lParam);
+
+        // We had to create our own splash screen so that Windows would automatically transfer focus from the other process's splash screen.
+        // Try to make sure new splash screen has painted before closing old one to avoid flickering.
+        if (pSplashScreen->hwndPrevious)
+        {
+            ::PostMessageW(pSplashScreen->hwndPrevious, WM_CLOSE, 0, 0);
+            pSplashScreen->hwndPrevious = NULL;
+        }
+
+        return lres;
     }
 
     return ::DefWindowProcW(hWnd, uMsg, wParam, lParam);
@@ -276,6 +290,11 @@ static HRESULT LoadSplashScreen(
     DPIU_MONITOR_CONTEXT* pMonitorContext = NULL;
     RECT* pMonitorRect = NULL;
 
+    if (::IsWindow(*pContext->pHwnd))
+    {
+        pSplashScreen->hwndPrevious = *pContext->pHwnd;
+    }
+
     pSplashScreen->nDpi = USER_DEFAULT_SCREEN_DPI;
     pSplashScreen->hBitmap = ::LoadBitmapW(pContext->hInstance, MAKEINTRESOURCEW(pContext->pSplashScreenConfiguration->wResourceId));
     ExitOnNullWithLastError(pSplashScreen->hBitmap, hr, "Failed to load splash screen bitmap.");
diff --git a/src/test/burn/WixToolsetTest.BurnE2E/WixIuiBaTests.cs b/src/test/burn/WixToolsetTest.BurnE2E/WixIuiBaTests.cs
index 18dd41db..3e7e3ded 100644
--- a/src/test/burn/WixToolsetTest.BurnE2E/WixIuiBaTests.cs
+++ b/src/test/burn/WixToolsetTest.BurnE2E/WixIuiBaTests.cs
@@ -114,7 +114,7 @@ namespace WixToolsetTest.BurnE2E
         // Manual test for InternalUIBundle:
         //  1. Double click InternalUIBundle.exe on a machine that will prompt for elevation.
         //  2. Verify that the splash screen appeared but the prereq BA did not come up.
-        //  3. Verify that the elevation prompt came up immediately instead of flashing on the taskbar. (This is currently broken)
+        //  3. Verify that the elevation prompt came up immediately instead of flashing on the taskbar.
         //  4. Allow elevation.
         //  5. Verify that the MSI UI came up and the splash screen disappeared.
         //  6. Accept the two CA messages and click the install button.