bug#7190: Crash in menus on w32

[grischka]

Here's a patch that fixes the bug.  Actually 4 bugs:
1) the initial cause: was freeing items prematurely and trying to
    free already freed items
2) memory leak: was trying to free items from already deleted menu
3) memory leak: was trying to free menu from already deleted window
4) other: was trying to set cursor in window with no associated frame

--- grischka

commit 064225db78640a1fb48b68aac603c8e05cc69b80
Author: grischka <grischka>
Date:   Thu Oct 14 13:23:38 2010 +0200

    fix w32menu ownerdraw string alloc/free

diff --git a/src/w32fns.c b/src/w32fns.c
index 8085035..83d577e 100644
--- a/src/w32fns.c
+++ b/src/w32fns.c
@@ -76,7 +76,6 @@ extern void free_frame_menubar (struct frame *);
 extern double atof (const char *);
 extern int w32_console_toggle_lock_key (int, Lisp_Object);
 extern void w32_menu_display_help (HWND, HMENU, UINT, UINT);
-extern void w32_free_menu_strings (HWND);
 extern const char *map_w32_filename (const char *, const char **);
 
 extern int quit_char;
@@ -280,12 +279,7 @@ unsigned int msh_mousewheel = 0;
 /* Timers */
 #define MOUSE_BUTTON_ID        1
 #define MOUSE_MOVE_ID  2
-#define MENU_FREE_ID 3
 #define HOURGLASS_ID 4
-/* The delay (milliseconds) before a menu is freed after WM_EXITMENULOOP
-   is received.  */
-#define MENU_FREE_DELAY 1000
-static unsigned menu_free_timer = 0;
 
 /* In dispnew.c */
 
@@ -3387,21 +3381,6 @@ w32_wnd_proc (HWND hwnd, UINT msg, WPARAM wParam, LPARAM 
lParam)
          KillTimer (hwnd, mouse_move_timer);
          mouse_move_timer = 0;
        }
-      else if (wParam == menu_free_timer)
-       {
-         KillTimer (hwnd, menu_free_timer);
-         menu_free_timer = 0;
-         f = x_window_to_frame (dpyinfo, hwnd);
-          /* If a popup menu is active, don't wipe its strings.  */
-         if (menubar_in_use
-              && current_popup_menu == NULL)
-           {
-             /* Free memory used by owner-drawn and help-echo strings.  */
-             w32_free_menu_strings (hwnd);
-             f->output_data.w32->menubar_active = 0;
-              menubar_in_use = 0;
-           }
-       }
       else if (wParam == hourglass_timer)
        {
          KillTimer (hwnd, hourglass_timer);
@@ -3465,14 +3444,11 @@ w32_wnd_proc (HWND hwnd, UINT msg, WPARAM wParam, 
LPARAM lParam)
     case WM_EXITMENULOOP:
       f = x_window_to_frame (dpyinfo, hwnd);
 
-      /* If a menu is still active, check again after a short delay,
-        since Windows often (always?) sends the WM_EXITMENULOOP
-        before the corresponding WM_COMMAND message.
-         Don't do this if a popup menu is active, since it is only
-         menubar menus that require cleaning up in this way.
-      */
       if (f && menubar_in_use && current_popup_menu == NULL)
-       menu_free_timer = SetTimer (hwnd, MENU_FREE_ID, MENU_FREE_DELAY, NULL);
+       {
+         f->output_data.w32->menubar_active = 0;
+         menubar_in_use = 0;
+       }
 
       /* If hourglass cursor should be displayed, display it now.  */
       if (f && f->output_data.w32->hourglass_p)
@@ -3632,15 +3608,6 @@ w32_wnd_proc (HWND hwnd, UINT msg, WPARAM wParam, LPARAM 
lParam)
       goto command;
     case WM_COMMAND:
       menubar_in_use = 0;
-      f = x_window_to_frame (dpyinfo, hwnd);
-      if (f && HIWORD (wParam) == 0)
-       {
-         if (menu_free_timer)
-           {
-             KillTimer (hwnd, menu_free_timer);
-             menu_free_timer = 0;
-           }
-       }
     case WM_MOVE:
     case WM_SIZE:
     command:
@@ -3748,6 +3715,8 @@ w32_wnd_proc (HWND hwnd, UINT msg, WPARAM wParam, LPARAM 
lParam)
       if (LOWORD (lParam) == HTCLIENT)
        {
          f = x_window_to_frame (dpyinfo, hwnd);
+         if (!f)
+           return 0;
          if (f->output_data.w32->hourglass_p && !menubar_in_use
              && !current_popup_menu)
            SetCursor (f->output_data.w32->hourglass_cursor);
diff --git a/src/w32menu.c b/src/w32menu.c
index ff6bd97..78d59fc 100644
--- a/src/w32menu.c
+++ b/src/w32menu.c
@@ -108,7 +108,7 @@ static Lisp_Object simple_dialog_show (FRAME_PTR, 
Lisp_Object, Lisp_Object);
 static void utf8to16 (unsigned char *, int, WCHAR *);
 static int fill_in_menu (HMENU, widget_value *);
 
-void w32_free_menu_strings (HWND);
+static void w32_free_menu_strings (HMENU);
 
 
 /* This is set nonzero after the user activates the menu bar, and set
@@ -347,8 +347,6 @@ menubar_selection_callback (FRAME_PTR f, void * client_data)
              buf.kind = MENU_BAR_EVENT;
              buf.frame_or_window = frame;
              buf.arg = entry;
-             /* Free memory used by owner-drawn and help-echo strings.  */
-             w32_free_menu_strings (FRAME_W32_WINDOW (f));
              kbd_buffer_store_event (&buf);
 
              f->output_data.w32->menubar_active = 0;
@@ -357,8 +355,6 @@ menubar_selection_callback (FRAME_PTR f, void * client_data)
          i += MENU_ITEMS_ITEM_LENGTH;
        }
     }
-  /* Free memory used by owner-drawn and help-echo strings.  */
-  w32_free_menu_strings (FRAME_W32_WINDOW (f));
   f->output_data.w32->menubar_active = 0;
 }
 
@@ -588,6 +584,7 @@ set_frame_menubar (FRAME_PTR f, int first_time, int deep_p)
 
   if (menubar_widget)
     {
+      w32_free_menu_strings (menubar_widget);
       /* Empty current menubar, rather than creating a fresh one.  */
       while (DeleteMenu (menubar_widget, 0, MF_BYPOSITION))
        ;
@@ -643,6 +640,7 @@ free_frame_menubar (FRAME_PTR f)
     HMENU old = GetMenu (FRAME_W32_WINDOW (f));
     SetMenu (FRAME_W32_WINDOW (f), NULL);
     f->output_data.w32->menubar_widget = NULL;
+    w32_free_menu_strings (old);
     DestroyMenu (old);
   }
 
@@ -898,10 +896,11 @@ w32_menu_show (FRAME_PTR f, int x, int y, int for_click, 
int keymaps,
   /* Free the widget_value objects we used to specify the contents.  */
   free_menubar_widget_value_tree (first_wv);
 
+  /* Free the owner-drawn and help-echo menu strings.  */
+  w32_free_menu_strings (menu);
   DestroyMenu (menu);
+  current_popup_menu = NULL;
 
-  /* Free the owner-drawn and help-echo menu strings.  */
-  w32_free_menu_strings (FRAME_W32_WINDOW (f));
   f->output_data.w32->menubar_active = 0;
 
   /* Find the selected item, and its pane, to return
@@ -1651,9 +1650,11 @@ w32_menu_display_help (HWND owner, HMENU menu, UINT 
item, UINT flags)
 
 /* Free memory used by owner-drawn strings.  */
 static void
-w32_free_submenu_strings (HMENU menu)
+w32_free_menu_strings (HMENU menu)
 {
   int i, num = GetMenuItemCount (menu);
+  if (!get_menu_item_info)
+    return;
   for (i = 0; i < num; i++)
     {
       MENUITEMINFO info;
@@ -1674,29 +1675,10 @@ w32_free_submenu_strings (HMENU menu)
 
       /* Recurse down submenus.  */
       if (info.hSubMenu)
-       w32_free_submenu_strings (info.hSubMenu);
+       w32_free_menu_strings (info.hSubMenu);
     }
 }
 
-void
-w32_free_menu_strings (HWND hwnd)
-{
-  HMENU menu = current_popup_menu;
-
-  if (get_menu_item_info)
-    {
-      /* If there is no popup menu active, free the strings from the frame's
-        menubar.  */
-      if (!menu)
-       menu = GetMenu (hwnd);
-
-      if (menu)
-       w32_free_submenu_strings (menu);
-    }
-
-  current_popup_menu = NULL;
-}
-
 #endif /* HAVE_MENUS */
 
 /* The following is used by delayed window autoselection.  */
diff --git a/src/w32term.c b/src/w32term.c
index 1f53860..0cef1b7 100644
--- a/src/w32term.c
+++ b/src/w32term.c
@@ -5734,11 +5734,11 @@ x_free_frame_resources (struct frame *f)
   if (FRAME_FACE_CACHE (f))
     free_frame_faces (f);
 
+  free_frame_menubar (f);
+
   if (FRAME_W32_WINDOW (f))
     my_destroy_window (f, FRAME_W32_WINDOW (f));
 
-  free_frame_menubar (f);
-
   unload_color (f, FRAME_FOREGROUND_PIXEL (f));
   unload_color (f, FRAME_BACKGROUND_PIXEL (f));
   unload_color (f, f->output_data.w32->cursor_pixel);