win32: never call GetClientRect(0, ...)

Sometimes GetClientRect() appeared to fail during init, and since we
don't check GetClientRect() calls (because they're on our own window,
and logically can never fail), bogus resizes were triggered. This could
cause vo_direct3d to fail initialization.

The reason was that w32->window was set to 0 during early window
initialization: CreateWindow*() can send messages to the new window,
even though it hasn't returned yet. This means w32->window is not yet
set to our window handle, and functions in WndProc may accidentally pass
hwnd=0 to win32 API functions.

Fix it by initializing w32->window on opportunity. This also means we
always strictly expect that the WndProc is used with our own window
only.

1 files changed, 4 insertions, 1 deletions

diff --git a/video/out/w32_common.c b/video/out/w32_common.c
index bc2a700975..f59c3cc259 100644
--- a/video/out/w32_common.c
+++ b/video/out/w32_common.c
@@ -515,6 +515,9 @@ static LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam,
 {
     assert(w32_thread_context);
     struct vo_w32_state *w32 = w32_thread_context;
+    if (!w32->window)
+        w32->window = hWnd; // can happen during CreateWindow*!
+    assert(w32->window == hWnd);
     int mouse_button = 0;
 
     switch (message) {
@@ -522,7 +525,7 @@ static LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam,
         // This message is used to wakeup the GUI thread, see wakeup_gui_thread.
         mp_dispatch_queue_process(w32->dispatch, 0);
         break;
-    case WM_ERASEBKGND: // no need to erase background seperately
+    case WM_ERASEBKGND: // no need to erase background separately
         return 1;
     case WM_PAINT:
         signal_events(w32, VO_EVENT_EXPOSE);