[PATCH 10/12] user32/tests: Synchronize with other thread between SendMessage calls.

[Rémi Bernon]

This sometimes fails on Windows because we check the queue status before
the other thread second call to SendMessage has been made (or received).

Adding a synchronization here could help, although there should not be
any long delay as we already seen the first SendMessage call -asserted
by the send_message_1 sequence.

https://testbot.winehq.org/JobDetails.pl?Key=59890#k106

Signed-off-by: Rémi Bernon 
---
 dlls/user32/tests/msg.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/dlls/user32/tests/msg.c b/dlls/user32/tests/msg.c
index c73f9ac36b9..593a1e65047 100644
--- a/dlls/user32/tests/msg.c
+++ b/dlls/user32/tests/msg.c
@@ -17475,6 +17475,7 @@ static DWORD WINAPI SendMessage_thread_1(void *param)

trace("thread: call SendMessage\n");
     SendMessageA(wnd_event->hwnd, WM_USER+2, 0, 0);
+    SetEvent(wnd_event->stop_event);

trace("thread: call SendMessage\n");
     SendMessageA(wnd_event->hwnd, WM_USER+3, 0, 0);
@@ -17501,6 +17502,7 @@ static DWORD WINAPI SendMessage_thread_2(void *param)

trace("thread: call SendMessage\n");
     SendMessageA(wnd_event->hwnd, WM_USER+2, 0, 0);
+    SetEvent(wnd_event->stop_event);

trace("thread: call SendMessage\n");
     SendMessageA(wnd_event->hwnd, WM_USER+3, 0, 0);
@@ -17517,6 +17519,7 @@ static void test_SendMessage_other_thread(int thread_n)
     MSG msg;

wnd_event.start_event = CreateEventA(NULL, 0, 0, NULL);
+    wnd_event.stop_event = CreateEventA(NULL, 0, 0, NULL);

wnd_event.hwnd = CreateWindowExA(0, "TestWindowClass", NULL, WS_OVERLAPPEDWINDOW,
                                      100, 100, 200, 200, 0, 0, 0, NULL);
@@ -17551,6 +17554,10 @@ static void test_SendMessage_other_thread(int thread_n)
     DispatchMessageA(&msg);
     ok_sequence(send_message_1, "SendMessage from other thread 1", thread_n == 2);

+    ret = WaitForSingleObject(wnd_event.stop_event, 100);
+    todo_wine_if (thread_n == 2)
+    ok(ret == WAIT_OBJECT_0, "WaitForSingleObject failed, ret:%x\n", ret);
+
     /* intentionally yield */
     MsgWaitForMultipleObjects(0, NULL, FALSE, 100, qs_all_input);

@@ -17587,6 +17594,9 @@ todo_wine_if (thread_n == 2)

flush_events();
     flush_sequence();
+
+    CloseHandle(wnd_event.start_event);
+    CloseHandle(wnd_event.stop_event);
 }

static LRESULT CALLBACK insendmessage_wnd_proc( HWND hwnd, UINT msg, WPARAM wp, LPARAM lp )