From efd14e4595e06eb83df1a858e8ba19e33f8e9f83 Mon Sep 17 00:00:00 2001
From: Fred Fish <fnf@specifix.com>
Date: Sat, 20 Jul 1996 17:21:36 +0000
Subject: [PATCH] 	* gdbtk.tcl (delete_expr): Unset corresponding element
 of 	expr_update_list when destroying an expression. 
 (create_expr_window): Initialize expr_num, delete_expr_num, 	and
 expr_update_list here when each new expression window 	is created, rather
 than once at startup. PR 9383

---
 gdb/ChangeLog |  8 ++++++++
 gdb/gdbtk.tcl | 21 +++++++++++++++------
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index d0fabdef697..bb030eb1677 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,11 @@
+Sat Jul 20 10:09:28 1996  Fred Fish  <fnf@cygnus.com>
+
+	* gdbtk.tcl (delete_expr): Unset corresponding element of
+	expr_update_list when destroying an expression.
+	(create_expr_window): Initialize expr_num, delete_expr_num,
+	and expr_update_list here when each new expression window
+	is created, rather than once at startup.
+
 Fri Jul 19 14:05:57 1996  Stan Shebs  <shebs@andros.cygnus.com>
 
 	* dwarf2read.c: New file, DWARF 2 reader originally contributed by
diff --git a/gdb/gdbtk.tcl b/gdb/gdbtk.tcl
index f517245cfa3..6d027cca303 100644
--- a/gdb/gdbtk.tcl
+++ b/gdb/gdbtk.tcl
@@ -27,7 +27,6 @@ set cfunc NIL
 set line_numbers 1
 set breakpoint_file(-1) {[garbage]}
 set disassemble_with_source nosource
-set expr_update_list(0) 0
 set gdb_prompt "(gdb) "
 
 # Hint: The following can be toggled from a tclsh window after
@@ -1089,9 +1088,6 @@ proc not_implemented_yet {message} {
 #	Create the expression display window.
 #
 
-set expr_num 0
-set delete_expr_num 0
-
 # Set delete_expr_num, and set -state of Delete button.
 proc expr_update_button {num} {
   global delete_expr_num
@@ -1135,13 +1131,14 @@ proc add_expr {expr} {
 
 proc delete_expr {} {
   global delete_expr_num
+  global expr_update_list
+
   if {$delete_expr_num > 0} then {
     set e .expr.exprs
     set f e${delete_expr_num}
 
     destroy $e.updates.$f $e.expressions.$f $e.values.$f
-
-    # FIXME should we unset an element of expr_update_list here?
+    unset expr_update_list($delete_expr_num)
   }
 }
 
@@ -1171,9 +1168,21 @@ proc update_exprs {} {
 }
 
 proc create_expr_window {} {
+	global expr_num
+	global delete_expr_num
+	global expr_update_list
 
 	if {[winfo exists .expr]} {raise .expr ; return}
 
+	# All the state about individual expressions is stored in the
+	# expression window widgets, so when it is deleted, the
+	# previous values of the expression global variables become
+	# invalid.  Reset to a known initial state.
+	set expr_num 0
+	set delete_expr_num 0
+	catch {unset expr_update_list}
+	set expr_update_list(0) 0
+
 	toplevel .expr
 	wm title .expr "GDB Expressions"
 	wm iconname .expr "Expressions"
-- 
2.30.2