From ad0fc9ca23717b46639d2f28a83437300499870d Mon Sep 17 00:00:00 2001
From: Matthias Melcher <fltk@matthiasm.com>
Date: Thu, 27 Apr 2006 21:40:47 +0000
Subject: STR #1162: Fl_Menu_Button::popup was trying to access a previously
 deleted widget (itself). The delayed deleting mechanism in
 'Fl::delete_widget' did not work in this case because the main loop is called
 before the callback returns. The fix implements a type of automatic pointer
 that will be cleared to NULL should the widget get deleted. This may not be a
 'nice' solution, but it does fix the problem reliably. We could actually use
 this for all widget pointers and remove the delayed delete mechanism
 alltogether

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.1@5037 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
---
 src/Fl.cxx             | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 src/Fl_Menu_Button.cxx |  5 ++++-
 src/Fl_Widget.cxx      |  1 +
 3 files changed, 52 insertions(+), 1 deletion(-)

(limited to 'src')

diff --git a/src/Fl.cxx b/src/Fl.cxx
index c9dcd0a6c..72ea71414 100644
--- a/src/Fl.cxx
+++ b/src/Fl.cxx
@@ -1207,6 +1207,53 @@ Fl::do_widget_deletion() {
   num_dwidgets = 0;
 }
 
+static Fl_Widget ***widget_watch = 0;
+static int num_widget_watch = 0;
+static int max_widget_watch = 0;
+
+void Fl::watch_widget_pointer(Fl_Widget *&w) 
+{
+  Fl_Widget **wp = &w;
+  int i;
+  for (i=0; i<num_widget_watch; ++i) {
+    if (widget_watch[i]==wp) return;
+  }
+  for (i=0; i<num_widget_watch; ++i) {
+    if (widget_watch[i]==0L) {
+      widget_watch[i] = wp;
+      return;
+    }
+  }
+  if (num_widget_watch==max_widget_watch) {
+    max_widget_watch += 8;
+    widget_watch = (Fl_Widget***)realloc(widget_watch, sizeof(Fl_Widget**)*max_widget_watch);
+  }
+  widget_watch[num_widget_watch++] = wp;
+}
+
+void Fl::release_widget_pointer(Fl_Widget *&w)
+{
+  Fl_Widget **wp = &w;
+  int i;
+  for (i=0; i<num_widget_watch; ++i) {
+    if (widget_watch[i]==wp) {
+      widget_watch[i] = 0L;
+      return;
+    }
+  }
+}
+
+void Fl::clear_widget_pointer(Fl_Widget const *w) 
+{
+  if (w==0L) return;
+  int i;
+  for (i=0; i<num_widget_watch; ++i) {
+    if (widget_watch[i] && *widget_watch[i]==w) {
+      *widget_watch[i] = 0L;
+    }
+  }
+}
+
 
 //
 // End of "$Id$".
diff --git a/src/Fl_Menu_Button.cxx b/src/Fl_Menu_Button.cxx
index 80768a6e0..a3c13a829 100644
--- a/src/Fl_Menu_Button.cxx
+++ b/src/Fl_Menu_Button.cxx
@@ -51,6 +51,8 @@ const Fl_Menu_Item* Fl_Menu_Button::popup() {
   const Fl_Menu_Item* m;
   pressed_menu_button_ = this;
   redraw();
+  Fl_Widget *mb = this;
+  Fl::watch_widget_pointer(mb);
   if (!box() || type()) {
     m = menu()->popup(Fl::event_x(), Fl::event_y(), label(), mvalue(), this);
   } else {
@@ -58,7 +60,8 @@ const Fl_Menu_Item* Fl_Menu_Button::popup() {
   }
   picked(m);
   pressed_menu_button_ = 0;
-  redraw();
+  if (mb) mb->redraw();
+  Fl::release_widget_pointer(mb);
   return m;
 }
 
diff --git a/src/Fl_Widget.cxx b/src/Fl_Widget.cxx
index 3c637767b..9f33b2cf3 100644
--- a/src/Fl_Widget.cxx
+++ b/src/Fl_Widget.cxx
@@ -133,6 +133,7 @@ extern void fl_throw_focus(Fl_Widget*); // in Fl_x.cxx
 // However, it is only legal to destroy a "root" such as an Fl_Window,
 // and automatic destructors may be called.
 Fl_Widget::~Fl_Widget() {
+  Fl::clear_widget_pointer(this);
   if (flags() & COPIED_LABEL) free((void *)(label_.value));
   parent_ = 0; // Don't throw focus to a parent widget.
   fl_throw_focus(this);
-- 
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