Fix subclassing to support nested messages.

dlls/comctl32/commctrl.c

@@ -114,6 +114,7 @@ extern void TREEVIEW_Unregister(void);
 extern void UPDOWN_Register(void);
 extern void UPDOWN_Unregister(void);
 
+static LRESULT WINAPI SubclassWndProc (HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
 
 LPSTR    COMCTL32_aSubclass = NULL;
 HMODULE COMCTL32_hModule = 0;
@@ -1108,10 +1109,10 @@ BOOL WINAPI SetWindowSubclass (HWND hWnd, SUBCLASSPROC pfnSubclass,
       /* set window procedure to our own and save the current one */
       if (IsWindowUnicode (hWnd))
          stack->origproc = (WNDPROC)SetWindowLongW (hWnd, GWL_WNDPROC,
-                                                   (LONG)DefSubclassProc);
+                                                   (LONG)SubclassWndProc);
       else
          stack->origproc = (WNDPROC)SetWindowLongA (hWnd, GWL_WNDPROC,
-                                                   (LONG)DefSubclassProc);
+                                                   (LONG)SubclassWndProc);
    } else {
       WNDPROC current;
       if (IsWindowUnicode (hWnd))
@@ -1119,7 +1120,7 @@ BOOL WINAPI SetWindowSubclass (HWND hWnd, SUBCLASSPROC pfnSubclass,
       else
          current = (WNDPROC)GetWindowLongA (hWnd, GWL_WNDPROC);
 
-      if (current != DefSubclassProc) {
+      if (current != SubclassWndProc) {
          ERR ("Application has subclassed with our procedure, then manually, then with us again.  The current implementation can't handle this.\n");
          return FALSE;
       }
@@ -1263,6 +1264,33 @@ BOOL WINAPI RemoveWindowSubclass(HWND hWnd, SUBCLASSPROC pfnSubclass, UINT_PTR u
 
 
 /***********************************************************************
+ * SubclassWndProc (internal)
+ *
+ * Window procedure for all subclassed windows. 
+ * Saves the current subclassing stack position to support nested messages
+ */
+
+static LRESULT WINAPI SubclassWndProc (HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
+{
+   LPSUBCLASS_INFO stack;
+   int stackpos;
+   LRESULT ret;
+
+   /* retrieve our little stack from the Properties */
+   stack = (LPSUBCLASS_INFO)GetPropA (hWnd, COMCTL32_aSubclass);
+   if (!stack) {
+      ERR ("Our sub classing stack got erased for %p!! Nothing we can do\n", hWnd);
+      return 0;
+   }
+   stackpos = stack->stackpos;
+   stack->stackpos = stack->stacknum;
+   ret = DefSubclassProc(hWnd,uMsg,wParam,lParam);
+   stack->stackpos = stackpos;
+   return ret;
+}
+
+
+/***********************************************************************
  * DefSubclassProc [COMCTL32.413]
  *
  * Calls the next window procedure (ie. the one before this subclass)