From f033d01527852268435dd8ab24ce875b4b0e5828 Mon Sep 17 00:00:00 2001
From: Christopher Chavez <chrischavez@gmx.us>
Date: Sat, 2 Sep 2023 03:53:36 -0500
Subject: [PATCH] gh-71383: add upstream fix

Adapted from https://core.tcl-lang.org/tk/info/b1876b9ebc4b
---
 generic/tkInt.h        |  3 ++-
 generic/tkWindow.c     |  1 +
 generic/ttk/ttkTheme.c | 26 +++++++++++++++++++-------
 3 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/generic/tkInt.h b/generic/tkInt.h
index 35b7e67380..7568585fad 100644
--- a/generic/tkInt.h
+++ b/generic/tkInt.h
@@ -1092,10 +1092,11 @@ extern "C" {
 #endif
 
 /*
- * Themed widget set init function:
+ * Themed widget set init function, and handler called when Tk is destroyed.
  */
 
 MODULE_SCOPE int	Ttk_Init(Tcl_Interp *interp);
+MODULE_SCOPE void	Ttk_TkDestroyedHandler(Tcl_Interp *interp);
 
 /*
  * Internal functions shared among Tk modules but not exported to the outside
diff --git a/generic/tkWindow.c b/generic/tkWindow.c
index fa2555354d..59c12433dd 100644
--- a/generic/tkWindow.c
+++ b/generic/tkWindow.c
@@ -1621,6 +1621,7 @@ Tk_DestroyWindow(
 	    TkFontPkgFree(winPtr->mainPtr);
 	    TkFocusFree(winPtr->mainPtr);
 	    TkStylePkgFree(winPtr->mainPtr);
+	    Ttk_TkDestroyedHandler(winPtr->mainPtr->interp);
 
 	    /*
 	     * When embedding Tk into other applications, make sure that all
diff --git a/generic/ttk/ttkTheme.c b/generic/ttk/ttkTheme.c
index 711c4107f8..09c7b15ebe 100644
--- a/generic/ttk/ttkTheme.c
+++ b/generic/ttk/ttkTheme.c
@@ -417,13 +417,6 @@ static void Ttk_StylePkgFree(
     Tcl_HashEntry *entryPtr;
     Cleanup *cleanup;
 
-    /*
-     * Cancel any pending ThemeChanged calls:
-     */
-    if (pkgPtr->themeChangePending) {
-	Tcl_CancelIdleCall(ThemeChangedProc, pkgPtr);
-    }
-
     /*
      * Free themes.
      */
@@ -531,6 +524,25 @@ static void ThemeChanged(StylePackageData *pkgPtr)
     }
 }
 
+/* Ttk_TkDestroyedHandler --
+ *	See bug [310c74ecf440]: idle calls to ThemeChangedProc()
+ *	need to be canceled when Tk is destroyed, since the interp
+ *	may still be active afterward; canceling them from
+ *	Ttk_StylePkgFree() would be too late.
+ */
+void Ttk_TkDestroyedHandler(
+    Tcl_Interp* interp)
+{
+    StylePackageData* pkgPtr = GetStylePackageData(interp);
+
+    /*
+     * Cancel any pending ThemeChanged calls:
+     */
+    if (pkgPtr->themeChangePending) {
+	Tcl_CancelIdleCall(ThemeChangedProc, pkgPtr);
+    }
+}
+
 /*
  * Ttk_CreateTheme --
  *	Create a new theme and register it in the global theme table.