[PATCH] ntdll: Execute queued APCs before starting a process.

[Zebediah Figura]

From: Sebastian Lackner

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=35561
Signed-off-by: Zebediah Figura 
---
The linked bug report is messy, but the the problem is essentially that Cygwin
queues an APC inside a DLL entry point which creates a thread, and expects that
thread to be running once the process starts (and without any alertable waits).

Tested with current 64-bit Cygwin; the installer runs to completion with this
patch, and hangs without it.

dlls/ntdll/loader.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/dlls/ntdll/loader.c b/dlls/ntdll/loader.c
index 376a8345f48..0ab25dcc51a 100644
--- a/dlls/ntdll/loader.c
+++ b/dlls/ntdll/loader.c
@@ -3540,6 +3540,7 @@ PIMAGE_NT_HEADERS WINAPI RtlImageNtHeader(HMODULE hModule)
  */
 void WINAPI LdrInitializeThunk( CONTEXT *context, void **entry, ULONG_PTR unknown3, ULONG_PTR unknown4 )
 {
+    static const LARGE_INTEGER zero;
     NTSTATUS status;
     WINE_MODREF *wm;
     LPCWSTR load_path = NtCurrentTeb()->Peb->ProcessParameters->DllPath.Buffer;
@@ -3602,6 +3603,8 @@ void WINAPI LdrInitializeThunk( CONTEXT *context, void **entry, ULONG_PTR unknow
     }

RtlLeaveCriticalSection( &loader_section );
+
+    NtDelayExecution( TRUE, &zero );
 }