user32: Add mouse tracking on caption right-clicks to avoid messing with the capture.

dlls/user32/controls.h

@@ -170,6 +170,7 @@ extern LRESULT NC_HandleNCActivate( HWND hwnd, WPARAM wParam, LPARAM lParam ) DE
 extern LRESULT NC_HandleNCCalcSize( HWND hwnd, WPARAM wParam, RECT *winRect ) DECLSPEC_HIDDEN;
 extern LRESULT NC_HandleNCHitTest( HWND hwnd, POINT pt ) DECLSPEC_HIDDEN;
 extern LRESULT NC_HandleNCLButtonDown( HWND hwnd, WPARAM wParam, LPARAM lParam ) DECLSPEC_HIDDEN;
+extern LRESULT NC_HandleNCRButtonDown( HWND hwnd, WPARAM wParam, LPARAM lParam ) DECLSPEC_HIDDEN;
 extern LRESULT NC_HandleNCLButtonDblClk( HWND hwnd, WPARAM wParam, LPARAM lParam) DECLSPEC_HIDDEN;
 extern LRESULT NC_HandleSysCommand( HWND hwnd, WPARAM wParam, LPARAM lParam ) DECLSPEC_HIDDEN;
 extern LRESULT NC_HandleSetCursor( HWND hwnd, WPARAM wParam, LPARAM lParam ) DECLSPEC_HIDDEN;

dlls/user32/defwnd.c

@@ -334,21 +334,11 @@ static LRESULT DEFWND_DefWinProc( HWND hwnd, UINT msg, WPARAM wParam, LPARAM lPa
         return NC_HandleNCLButtonDblClk( hwnd, wParam, lParam );
 
     case WM_NCRBUTTONDOWN:
-        /* in Windows, capture is taken when right-clicking on the caption bar */
+        return NC_HandleNCRButtonDown( hwnd, wParam, lParam );
-        if (wParam==HTCAPTION)
-        {
-            SetCapture(hwnd);
-        }
-        break;
 
     case WM_RBUTTONUP:
         {
             POINT pt;
-
-            if (hwnd == GetCapture())
-                /* release capture if we took it on WM_NCRBUTTONDOWN */
-                ReleaseCapture();
-
             pt.x = (short)LOWORD(lParam);
             pt.y = (short)HIWORD(lParam);
             ClientToScreen(hwnd, &pt);

dlls/user32/nonclient.c

@@ -1461,6 +1461,44 @@ LRESULT NC_HandleNCLButtonDown( HWND hwnd, WPARAM wParam, LPARAM lParam )
 }
 
 
+/***********************************************************************
+ *           NC_HandleNCRButtonDown
+ *
+ * Handle a WM_NCRBUTTONDOWN message. Called from DefWindowProc().
+ */
+LRESULT NC_HandleNCRButtonDown( HWND hwnd, WPARAM wParam, LPARAM lParam )
+{
+    MSG msg;
+    INT hittest = wParam;
+    HMENU hSysMenu = GetSystemMenu(hwnd, FALSE);
+
+    switch (hittest)
+    {
+    case HTCAPTION:
+    case HTSYSMENU:
+        hSysMenu = GetSystemMenu(hwnd, FALSE);
+        if (!hSysMenu) break;
+
+        SetCapture( hwnd );
+        for (;;)
+        {
+            if (!GetMessageW( &msg, 0, WM_MOUSEFIRST, WM_MOUSELAST )) break;
+            if (CallMsgFilterW( &msg, MSGF_MAX )) continue;
+            if (msg.message == WM_RBUTTONUP)
+            {
+                hittest = NC_HandleNCHitTest( hwnd, msg.pt );
+                break;
+            }
+        }
+        ReleaseCapture();
+        if (hittest == HTCAPTION || hittest == HTSYSMENU)
+            SendMessageW( hwnd, WM_SYSCOMMAND, SC_MOUSEMENU + HTSYSMENU, msg.lParam );
+        break;
+    }
+    return 0;
+}
+
+
 /***********************************************************************
  *           NC_HandleNCLButtonDblClk
  *