Win32 Application no longer terminates after using Windows GDI ChoosePixelFormat

Ilia Vorobyov 1

Since a few days my Win32 C++ application no longer terminates once the ExitInstance() function is finished. The same application was working fine a few weeks ago. The problem occurred on various of Terminal Servers when the Device Number of adjacent color bits for each pixel is 16 and I believe a gdi32.dll patch is the root cause.

Rita Han - MSFT 2,161 Reputation points

2020-11-26T06:23:56.76+00:00

Hello @Ilia Vorobyov , since c++ and winapi-general tags involve two kinds of application type: MFC and Win32. I want to confirm if you are talking about MFC application or Win32 application? So that we can redirect to the right team for more professional support.
Ilia Vorobyov 1 Reputation point

2020-11-26T07:55:09.137+00:00

It is MFC Application 32 bits with using Win32 API functions.
David Lowndes 4,711 Reputation points

2020-11-26T09:19:00.323+00:00

If you believe a gdi32.dll patch has been the cause, can you remove the update and resolves the problem?
Which update is it?
Ilia Vorobyov 1 Reputation point

2020-11-26T12:26:56.527+00:00

I can't remove the patch, because this occurs on several clients computers.
Jeanine Zhang-MSFT 9,181 Reputation points Microsoft Vendor

2020-11-27T06:12:41.823+00:00

@Ilia Vorobyov ,

Could you please share a minimal demo to help us reproduce the issue? Please don't include any private info in the demo.
Ilia Vorobyov 1 Reputation point

2020-11-27T07:20:10.33+00:00
int s_nColors = 32;
BOOL CMyApp::InitInstance()
{
...
HDC hDC = GetDC(NULL);
if(hDC)
{
s_nColors = ::GetDeviceCaps(hDC,BITSPIXEL);
if(s_nColors == 16)
{
PIXELFORMATDESCRIPTOR pfd = {
sizeof(PIXELFORMATDESCRIPTOR),
1,
PFD_DRAW_TO_WINDOW |
PFD_SUPPORT_OPENGL |
PFD_TYPE_RGBA,
24,
0, 0, 0, 0, 0, 0,
0,
0,
0,
0, 0, 0, 0,
32,
0,
0,
PFD_MAIN_PLANE,
0,
0, 0, 0
};

int iPixelFormat = ChoosePixelFormat(hDC, &pfd); if(iPixelFormat && DescribePixelFormat(hDC, iPixelFormat, sizeof(PIXELFORMATDESCRIPTOR), &pfd)) s_nColors = pfd.cRedBits + pfd.cGreenBits + pfd.cBlueBits; } ::ReleaseDC(NULL,hDC); }

...
}
Jeanine Zhang-MSFT 9,181 Reputation points Microsoft Vendor

2020-11-27T09:07:12.927+00:00

According to the code, I couldn't reproduce the issue, my application could terminates normally. As far as I'm concerned, as you said, a gdi32.dll patch is the root cause. I suggest you could send feedback to Microsoft with the Feedback Hub app: https://support.microsoft.com/en-us/windows/send-feedback-to-microsoft-with-the-feedback-hub-app-f59187f8-8739-22d6-ba93-f66612949332