From f271634296a952a7e0efdf8a7fe474e67367c7e5 Mon Sep 17 00:00:00 2001
From: Drew Ronneberg <drew_ronneberg@yahoo.com>
Date: Tue, 18 Nov 2014 22:30:37 -0500
Subject: [PATCH] user32: Do not call SendMessage() to hide a window that is
 already hidden.

---
 dlls/user32/tests/msg.c | 3 ---
 dlls/user32/winpos.c    | 3 +++
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/dlls/user32/tests/msg.c b/dlls/user32/tests/msg.c
index d829c5fbca1..28bb35e560b 100644
--- a/dlls/user32/tests/msg.c
+++ b/dlls/user32/tests/msg.c
@@ -4673,8 +4673,6 @@ static void test_messages(void)
     flush_events();
     ok_sequence(WmEmptySeq, "ShowWindow(SW_HIDE):overlapped", FALSE);
 
-    if (0)
-    {
     /* test ShowWindow(SW_HIDE) on a hidden window -  multi-threaded */
     hthread = CreateThread(NULL, 0, show_window_thread, hwnd, 0, &tid);
     ok(hthread != NULL, "CreateThread failed, error %d\n", GetLastError());
@@ -4682,7 +4680,6 @@ static void test_messages(void)
     CloseHandle(hthread);
     flush_events();
     ok_sequence(WmEmptySeq, "ShowWindow(SW_HIDE):overlapped", FALSE);
-    }
 
     ShowWindow(hwnd, SW_SHOW);
     flush_events();
diff --git a/dlls/user32/winpos.c b/dlls/user32/winpos.c
index 53737339d33..12d3ffa0325 100644
--- a/dlls/user32/winpos.c
+++ b/dlls/user32/winpos.c
@@ -1219,6 +1219,9 @@ BOOL WINAPI ShowWindow( HWND hwnd, INT cmd )
     if ((full_handle = WIN_IsCurrentThread( hwnd )))
         return show_window( full_handle, cmd );
 
+    if ((cmd == SW_HIDE) && !(GetWindowLongW( hwnd, GWL_STYLE ) & WS_VISIBLE))
+        return FALSE;
+
     return SendMessageW( hwnd, WM_WINE_SHOWWINDOW, cmd, 0 );
 }