From 87dc376df78ac62fa61c598b77085d66f234f2c2 Mon Sep 17 00:00:00 2001
From: stefan schippers <stefan.schippers@gmail.com>
Date: Sun, 28 Sep 2025 09:43:39 +0200
Subject: [PATCH] when closing all windows of xschem (in no tabbed mode) avoid
 unexpected context switches when the "unsaved data" alert is shown, possibly
 leading to segfault

---
 src/callback.c | 1 +
 src/xinit.c    | 9 ++++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/callback.c b/src/callback.c
index dd8acf55..d1391eff 100644
--- a/src/callback.c
+++ b/src/callback.c
@@ -4604,6 +4604,7 @@ static int handle_window_switching(int event, int tabbed_interface, const char *
         dbg(1, "callback(): switching window context: %s --> %s, semaphore=%d\n",
                 xctx->current_win_path, win_path, xctx->semaphore);
         new_schematic("switch", win_path, "", 1);
+        dbg(1, "switching to %s\n", win_path);
       }
 
     }
diff --git a/src/xinit.c b/src/xinit.c
index f67fb3c6..8d609317 100644
--- a/src/xinit.c
+++ b/src/xinit.c
@@ -1988,7 +1988,9 @@ static void destroy_all_windows(int *window_count, int force)
         else { 
           xctx = save_xctx[i];
           close = 0;
+          xctx->semaphore++; /* to avoid context switches when dialog below is shown */
           /* reset old focused window so callback() will force repaint on expose events */
+          dbg(1, "destroy_all_windows(): top_path=%s\n", xctx->top_path);
           if(!force && xctx->modified && has_x) {
             tcleval("tk_messageBox -type okcancel  -parent [xschem get topwindow] -message \""
                     "[get_cell [xschem get schname] 0]"
@@ -1996,16 +1998,21 @@ static void destroy_all_windows(int *window_count, int force)
             if(strcmp(tclresult(),"ok")==0) close = 1;
           }
           else close = 1;
+          xctx->semaphore--;
           Tcl_ResetResult(interp);
           if(close) {
             char *toplevel = NULL;
             if(has_x) {
               tclvareval("winfo toplevel ", window_path[i], NULL);
               my_strdup2(_ALLOC_ID_, &toplevel, tclresult());
+              dbg(1, "toplevel=%s\n", toplevel);
               tclvareval("store_geom ", toplevel, " [xschem get schname]", NULL);
             }
             /* set saved ctx to main window if previous is about to be destroyed */
-            if(savectx == save_xctx[i]) savectx = save_xctx[0];
+            if(savectx == save_xctx[i]) {
+              savectx = save_xctx[0];
+              dbg(1, "setting savectx to xctx[0]: current saved context=%s, i=%d\n", savectx->current_win_path, i);
+            }
             delete_schematic_data(1);
             save_xctx[i] = NULL;
             if(has_x) {