[PATCH] user32: Do not call SendMessage() to show a window that is already visible.

[Kimmo Myllyvirta]

On 04/30/2017 07:38 AM, Dmitry Timoshkov wrote:
> Kimmo Myllyvirta <kimmo.myllyvirta at gmail.com> wrote:
>
>> diff --git a/dlls/user32/winpos.c b/dlls/user32/winpos.c
>> index c2b35ec..64fdfe0 100644
>> --- a/dlls/user32/winpos.c
>> +++ b/dlls/user32/winpos.c
>> @@ -1239,6 +1239,9 @@ BOOL WINAPI ShowWindow( HWND hwnd, INT cmd )
>>       if ((cmd == SW_HIDE) && !(GetWindowLongW( hwnd, GWL_STYLE ) & WS_VISIBLE))
>>           return FALSE;
>>   
>> +    if ((cmd == SW_SHOW) && (GetWindowLongW( hwnd, GWL_STYLE ) & WS_VISIBLE))
>> +        return TRUE;
>> +
>>       return SendMessageW( hwnd, WM_WINE_SHOWWINDOW, cmd, 0 );
>>   }
> Please have a look at the show_window() implementation and try to cover
> all cases that trigger SWP_SHOWWINDOW flag passed to SetWindowPos() in
> order to actually show a window. In fact it's only SW_HIDE that leads
> to that, so perhaps just adding an 'else' to the SW_HIDE case is enough?
>

Yeah, it would be better to fix all the cases at once instead of 
one-by-one. Probably something similar to the attached diff. I'll take a 
look at it later, this is already fixed in staging it seems.

-------------- next part --------------
diff --git a/dlls/user32/winpos.c b/dlls/user32/winpos.c
index c2b35ec..d49be31 100644
--- a/dlls/user32/winpos.c
+++ b/dlls/user32/winpos.c
@@ -1227,6 +1227,8 @@ BOOL WINAPI ShowWindowAsync( HWND hwnd, INT cmd )
 BOOL WINAPI ShowWindow( HWND hwnd, INT cmd )
 {
     HWND full_handle;
+    LONG style;
+    BOOL wasVisible;
 
     if (is_broadcast(hwnd))
     {
@@ -1236,8 +1238,37 @@ 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;
+    style = GetWindowLongW( hwnd, GWL_STYLE );
+    wasVisible = (style & WS_VISIBLE) != 0;
+
+    switch(cmd)
+    {
+        case SW_HIDE:
+            if (!wasVisible) return FALSE;
+            break;
+        case SW_SHOWMINNOACTIVE:
+        case SW_MINIMIZE:
+        case SW_FORCEMINIMIZE:
+        case SW_SHOWMINIMIZED:
+            if ((style & WS_MINIMIZE) && wasVisible) return TRUE;
+            break;
+        case SW_SHOWMAXIMIZED:
+            if ((style & WS_MAXIMIZE) && wasVisible) return TRUE;
+            break;
+        case SW_SHOWNA:
+            break;
+        case SW_SHOW:
+            if (wasVisible) return TRUE;
+            break;
+        case SW_SHOWNOACTIVATE:
+        case SW_RESTORE:
+        case SW_SHOWNORMAL:
+        case SW_SHOWDEFAULT:
+            if (!(style & (WS_MINIMIZE | WS_MAXIMIZE)) && wasVisible) return TRUE;
+            break;
+        default:
+            return wasVisible;
+    }
 
     return SendMessageW( hwnd, WM_WINE_SHOWWINDOW, cmd, 0 );
 }