[xemacs-hg @ 2003-02-07 11:50:50 by ben] fixes for menu crashes + better preemption behavior This contains two related changes: (1) Fix problems with reentrant calling of lwlib and associated crashes when selecting menu items. (2) Improve redisplay handling of preemption. Turn on lazy lock and hold down page-down or page-up and you'll see what I mean. They are related because they both touch on the code that retrieves events and handles the internal queues. console-msw.h, event-msw.c, event-stream.c, events.h, menubar-msw.c, menubar-x.c, menubar.h: mswindows_protect_modal_loop() has been generalized to event_stream_protect_modal_loop(), and moved to event-stream.c. mswindows_in_modal_loop ->in_modal_loop likewise. Changes in event-msw.c and menubar-msw.c for the new names and calling format (use structures instead of static variables in menubar-msw.c). Delete former in_menu_callback and use in_modal_loop in its place. Remove emacs_mswindows_quit_check_disallowed_p(), superseded by in_modal_loop. Use event_stream_protect_modal_loop() in pre_activate_callback() so that we get no lwlib reentrancy. Rearrange some of the code in event-msw.c to be grouped better. Make mswindows_drain_windows_queue() respect in_modal_loop and do nothing if so. cmdloop.c, event-stream.c: Don't conditionalize on LWLIB_MENUBARS_LUCID when giving error when in_modal_loop, and give better error. event-Xt.c, event-gtk.c: If in_modal_loop, only retrieve process and timeout events. Don't retrieve any X events because processing them can lead to reentrancy in lwlib -> death. event-stream.c: Remove unused parameter to check_event_stream_ok() and change all callers. lisp.h, event-stream.c: Rearrange some functions for increased clarity -- in particular, group all the input-pending/QUIT-related stuff together, and put right next to next-event stuff, to which it's related. Add the concept of "HOW_MANY" -- when asking whether user input is pending, you can ask if at least HOW_MANY events are pending, not just if any are. Add parameter to detect_input_pending() for this. Change recursive_sit_for from a Lisp_Object (which could only be Qt or Qnil) to an int, like it should be. event-Xt.c, event-gtk.c, event-xlike-inc.c: New file. Abstract out similar code in event_{Xt/gtk}_pending_p() and write only once, using include-file tricks. Rewrite this function to implement HOW_MANY and only process events when not in_modal_loop. event-msw.c: Implement HOW_MANY and only process events when not in_modal_loop. event-tty.c: Implement HOW_MANY. redisplay.c: Add var `max-preempts' to control maximum number of preempts. (#### perhaps not useful) Rewrite preemption check so that, rather than preempting when any user events are available, only preempt when a certain number (currently 4) of them are backed up. This effectively allows redisplay to proceed to completion in the presence of a fast auto-repeat (usually the auto-repeating is generated dynamically as necessary), and you get much better display behavior with lazy-lock active. event-unixoid.c: Comment changes. event-stream.c: Rewrite discard-input much more simply and safely using the drain-queue functions. I think the old version might loop forever if called when in_modal_loop. SEMI-UNRELATED CHANGES: ----------------------- event-stream.c: Turn QUIT-checking back on when running the pre-idle hook so it can be quit out of. indent.c: Document exact functioning of `vertical-motion' better, and its differences from GNU Emacs.

--- a/src/menubar-x.c	Fri Feb 07 01:43:07 2003 +0000
+++ b/src/menubar-x.c	Fri Feb 07 11:50:54 2003 +0000
@@ -396,18 +396,15 @@
   midtwv.filter_p = filter_p;
 
   if (UNBOUNDP
-      (call_trapping_problems
-       (Qmenubar, "Error during menu callback",	UNINHIBIT_QUIT, 0,
-	protected_menu_item_descriptor_to_widget_value_1, &midtwv)))
+      (event_stream_protect_modal_loop
+       ("Error during menu callback",
+	protected_menu_item_descriptor_to_widget_value_1, &midtwv,
+	UNINHIBIT_QUIT)))
     return 0;
 
   return midtwv.wv;
 }
 
-#if defined (LWLIB_MENUBARS_LUCID) || (defined LWLIB_MENUBARS_MOTIF)
-int in_menu_callback;
-#endif
-
 /* The order in which callbacks are run is funny to say the least.
    It's sometimes tricky to avoid running a callback twice, and to
    avoid returning prematurely.  So, this function returns true
@@ -435,7 +432,6 @@
   struct device *d = get_device_from_display (XtDisplay (widget));
   struct frame *f = x_any_window_to_frame (d, XtWindow (widget));
   Lisp_Object frame;
-  int count;
 
   /* set in lwlib to the time stamp associated with the most recent menu
      operation */
@@ -460,17 +456,8 @@
       assert (hack_wv->type == INCREMENTAL_TYPE);
       submenu_desc = VOID_TO_LISP (hack_wv->call_data);
 
-      /*
-       * #### Fix the menu code so this isn't necessary.
-       *
-       * Protect against reentering the menu code otherwise we will
-       * crash later when the code gets confused at the state
-       * changes.
-       */
-      count = internal_bind_int (&in_menu_callback, 1);
       wv = (protected_menu_item_descriptor_to_widget_value
 	    (submenu_desc, SUBMENU_TYPE, 1, 0));
-      unbind_to (count);
 
       if (!wv)
 	{