ddraw: Prevent ddraw from being unloaded.

dlls/ddraw/main.c

@@ -812,6 +812,7 @@ DllMain(HINSTANCE hInstDLL,
     TRACE("(%p,%x,%p)\n", hInstDLL, Reason, lpv);
     if (Reason == DLL_PROCESS_ATTACH)
     {
+        static HMODULE ddraw_self;
         char buffer[MAX_PATH+10];
         DWORD size = sizeof(buffer);
         HKEY hkey = 0;
@@ -911,6 +912,16 @@ DllMain(HINSTANCE hInstDLL,
             RegCloseKey( hkey );
         }
 
+        /* Prevent the ddraw module from being unloaded. When switching to
+         * exclusive mode, we replace the window proc of the ddraw window. If
+         * an application would unload ddraw from the WM_DESTROY handler for
+         * that window, it would return to unmapped memory and die. Apparently
+         * this is supposed to work on Windows. We should probably use
+         * GET_MODULE_HANDLE_EX_FLAG_PIN for this, but that's not currently
+         * implemented. */
+        if (!GetModuleHandleExW(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS, (const WCHAR *)&ddraw_self, &ddraw_self))
+            ERR("Failed to get own module handle.\n");
+
         instance = hInstDLL;
         DisableThreadLibraryCalls(hInstDLL);
     }