(w32_read_socket): Determine clipping rectangle for

the entire frame, including areas covered by scrollbars and the
menubar.  This avoids internal arguments about whether a frame is
fully obscured or not.

1 files changed, 12 insertions, 2 deletions

diff --git a/src/w32term.c b/src/w32term.c
index 8478f6c8b5e..0425ed44577 100644
--- a/src/w32term.c
+++ b/src/w32term.c
@@ -8713,9 +8713,19 @@ w32_read_socket (sd, bufp, numchars, expected)
           if (FRAME_W32_P (f) && f->async_visible)
             {
               RECT clipbox;
-              HDC  hdc = get_frame_dc (f);
+              HDC  hdc;
+
+              enter_crit ();
+              /* Query clipping rectangle for the entire window area
+                 (GetWindowDC), not just the client portion (GetDC).
+                 Otherwise, the scrollbars and menubar aren't counted as
+                 part of the visible area of the frame, and we may think
+                 the frame is obscured when really a scrollbar is still
+                 visible and gets WM_PAINT messages above.  */
+              hdc = GetWindowDC (FRAME_W32_WINDOW (f));
               GetClipBox (hdc, &clipbox);
-              release_frame_dc (f, hdc);
+              ReleaseDC (FRAME_W32_WINDOW (f), hdc);
+              leave_crit ();
 
               if (clipbox.right == clipbox.left
                   || clipbox.bottom == clipbox.top)