Accepting request 1085488 from home:WernerFink:branches:X11:windowmanagers

- Add patch threadlocking.patch
  * Fix for lock recusion in handle_all_expose() to handle if
    libX11 1.8.1 and above enables X display locks unconditionnaly

OBS-URL: https://build.opensuse.org/request/show/1085488
OBS-URL: https://build.opensuse.org/package/show/X11:windowmanagers/fvwm2?expand=0&rev=51

fvwm2.changes

@@ -1,3 +1,10 @@
+-------------------------------------------------------------------
+Thu May  4 07:30:15 UTC 2023 - Dr. Werner Fink <werner@suse.de>
+
+- Add patch threadlocking.patch
+  * Fix for lock recusion in handle_all_expose() to handle if
+    libX11 1.8.1 and above enables X display locks unconditionnaly
+
 -------------------------------------------------------------------
 Tue Jan 31 14:22:50 UTC 2023 - Reinhard Max <max@suse.com>
 

fvwm2.spec

@@ -33,6 +33,7 @@ Patch1:         fvwm-2.5.26-sv_SE.patch
 Patch2:         fvwm-no-date-time.patch
 Patch3:         enable-more-mouse-buttons.patch
 Patch4:         fvwm-FvwmAuto-overflow.patch
+Patch5:         threadlocking.patch
 BuildRequires:  automake
 BuildRequires:  gcc-c++
 BuildRequires:  libpng-devel

threadlocking.patch

@@ -0,0 +1,105 @@
+From 58cc099368de9b0dd8bf5d2daa0f31d5c373f812 Mon Sep 17 00:00:00 2001
+From: Thomas Adam <thomas@xteddy.org>
+Date: Tue, 2 May 2023 16:53:10 +0100
+Subject: [PATCH] debian bug 1034054: backport fvwm3 xthreadlock()
+
+Backport this fix from fvwm3 to fvwm2:
+
+https://github.com/fvwmorg/fvwm3/commit/5c17c83df4605d2d97999740cf180af983298896
+
+XCheckIfEvent() holds the X display lock and the predicate
+function it calls is not allowed to call any Xlib function that
+would re-enter the lock.
+libX11 1.8.1 enables X display locks unconditionnaly (it was only
+enabled by XInitThreads() when called explicitely before) and
+thus exposes the issue.
+
+So don't process events in the FCheckPeekIfEvent() predicate, but
+instead use a separate handler that is called for the returned event
+out of the lock.
+
+---
+ fvwm/events.c |  9 ++++++++-
+ libs/FEvent.c | 22 ++++++++++++++++++++++
+ libs/FEvent.h |  8 ++++++++
+ 3 files changed, 38 insertions(+), 1 deletion(-)
+
+diff --git a/fvwm/events.c b/fvwm/events.c
+index a2d024068..7a3d06c3b 100644
+--- fvwm/events.c
++++ fvwm/events.c
+@@ -258,6 +258,12 @@ static int _pred_weed_accumulate_expose(
+ 	return 1;
+ }
+ 
++static int _pred_weed_is_expose(
++	Display *display, XEvent *event, XPointer arg)
++{
++	return (event->type == Expose);
++}
++
+ static int _pred_weed_handle_expose(
+ 	Display *display, XEvent *event, XPointer arg)
+ {
+@@ -4542,7 +4548,8 @@ void handle_all_expose(void)
+ 
+ 	saved_event = fev_save_event();
+ 	FPending(dpy);
+-	FWeedIfEvents(dpy, _pred_weed_handle_expose, NULL);
++	FWeedAndHandleIfEvents(dpy, _pred_weed_is_expose,
++			       _pred_weed_handle_expose, NULL);
+ 	fev_restore_event(saved_event);
+ 
+ 	return;
+diff --git a/libs/FEvent.c b/libs/FEvent.c
+index 24d019dd1..ec31728a9 100644
+--- libs/FEvent.c
++++ libs/FEvent.c
+@@ -532,6 +532,28 @@ int FWeedIfEvents(
+ 	return weed_args.count;
+ }
+ 
++int FWeedAndHandleIfEvents(
++	Display *display,
++	int (*weed_predicate) (Display *display, XEvent *event, XPointer arg),
++	int (*handler) (Display *display, XEvent *event, XPointer arg),
++	XPointer arg)
++{
++	_fev_weed_args weed_args;
++	XEvent e;
++
++	assert(fev_is_invalid_event_type_set);
++	memset(&weed_args, 0, sizeof(weed_args));
++	weed_args.weed_predicate = weed_predicate;
++	weed_args.arg = arg;
++	if (FCheckPeekIfEvent(display, &e, _fev_pred_weed_if,
++			      (XPointer)&weed_args)) {
++		handler(display, &e, arg);
++	}
++	_fev_pred_weed_if_finish(&weed_args);
++
++	return weed_args.count;
++}
++
+ int FWeedIfWindowEvents(
+ 	Display *display, Window window,
+ 	int (*weed_predicate) (
+diff --git a/libs/FEvent.h b/libs/FEvent.h
+index 821aef51a..2622f4474 100644
+--- libs/FEvent.h
++++ libs/FEvent.h
+@@ -113,6 +113,14 @@ int FWeedIfEvents(
+ 		Display *display, XEvent *current_event, XPointer arg),
+ 	XPointer arg);
+ 
++/* Same as FWeedIfEvents but with a second callback out of XLockDisplay()
++ * to handle events in a lock-safe manner */
++int FWeedAndHandleIfEvents(
++	Display *display,
++	int (*weed_predicate) (Display *display, XEvent *event, XPointer arg),
++	int (*handler) (Display *display, XEvent *event, XPointer arg),
++	XPointer arg);
++
+ /* Same as FWeedIfEvents but weeds only events for the given window.  The
+  * weed_predicate is only called for events with a matching window.  */
+ int FWeedIfWindowEvents(