[PATCH 2/2] win32u: Post WM_MOUSELEAVE immediately when the cursor is not in the specified tracking window.

[Zhiyi Zhang]

From: Zhiyi Zhang

Fix erwin Data Modeler unable click its comboboxes in listboxes.
---
 dlls/user32/tests/msg.c |  2 +-
 dlls/win32u/input.c     | 11 +++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/dlls/user32/tests/msg.c b/dlls/user32/tests/msg.c
index 83364c32695..9282896262e 100644
--- a/dlls/user32/tests/msg.c
+++ b/dlls/user32/tests/msg.c
@@ -15057,7 +15057,7 @@ static void test_TrackMouseEvent(void)
     ret = pTrackMouseEvent(&tme);
     ok(ret, "TrackMouseEvent(TME_LEAVE) failed, error %ld\n", GetLastError());
     flush_events();
-    ok_sequence(WmMouseLeaveSeq, "WmMouseLeaveSeq", TRUE);
+    ok_sequence(WmMouseLeaveSeq, "WmMouseLeaveSeq", FALSE);

DestroyWindow(hwnd2);
     DestroyWindow(hwnd);
diff --git a/dlls/win32u/input.c b/dlls/win32u/input.c
index e403b0f041d..424c4cff9f4 100644
--- a/dlls/win32u/input.c
+++ b/dlls/win32u/input.c
@@ -1813,6 +1813,17 @@ BOOL WINAPI NtUserTrackMouseEvent( TRACKMOUSEEVENT *info )
     }
     else
     {
+        /* If TME_LEAVE is set and when the mouse is not in the tracking window, post WM_MOUSELEAVE
+         * now and don't overwrite the current tracking information */
+        if (info->dwFlags & TME_LEAVE && !hwnd)
+        {
+            if (info->dwFlags & TME_NONCLIENT)
+                NtUserPostMessage( info->hwndTrack, WM_NCMOUSELEAVE, 0, 0 );
+            else
+                NtUserPostMessage( info->hwndTrack, WM_MOUSELEAVE, 0, 0 );
+            return TRUE;
+        }
+
         /* In our implementation, it's possible that another window will receive
          * WM_MOUSEMOVE and call TrackMouseEvent before TrackMouseEventProc is
          * called. In such a situation, post the WM_MOUSELEAVE now. */