Fixed [011706ec42] - tk::ButtonInvoke safety bug

FossilOrigin-Name: e1431c56fe45233411560153a8c52facd25b46fa

2 files changed, 34 insertions, 3 deletions

diff --git a/library/button.tcl b/library/button.tcl
index b2bafb2..80d8bf9 100644
--- a/library/button.tcl
+++ b/library/button.tcl
@@ -597,12 +597,25 @@ proc ::tk::ButtonUp w {
 # w -		The name of the widget.
 
 proc ::tk::ButtonInvoke w {
-    if {[$w cget -state] ne "disabled"} {
+    if {[winfo exists $w] && [$w cget -state] ne "disabled"} {
 	set oldRelief [$w cget -relief]
 	set oldState [$w cget -state]
 	$w configure -state active -relief sunken
-	update idletasks
-	after 100
+	after 100 [list ::tk::ButtonInvokeEnd $w $oldState $oldRelief]
+    }
+}
+
+# ::tk::ButtonInvokeEnd --
+# The procedure below is called after a button is invoked through
+# the keyboard.  It simulate a release of the button via the mouse.
+#
+# Arguments:
+# w -         The name of the widget.
+# oldState -  Old state to be set back.
+# oldRelief - Old relief to be set back.
+
+proc ::tk::ButtonInvokeEnd {w oldState oldRelief} {
+    if {[winfo exists $w]} {
 	$w configure -state $oldState -relief $oldRelief
 	uplevel #0 [list $w invoke]
     }
diff --git a/tests/button.test b/tests/button.test
index d28559a..28d8934 100644
--- a/tests/button.test
+++ b/tests/button.test
@@ -3908,6 +3908,24 @@ test button-13.8 {size behavior: checkbutton} -setup {
     destroy .a .b .c
 } -result {1 1 1}
 
+test button-14.1 {bug fix: [011706ec42] tk::ButtonInvoke unsafe wrt widget destruction} -body {
+    proc destroy_button {} {
+        if {[winfo exists .top.b]} {
+            destroy .top.b
+        }
+    }
+    toplevel .top
+    button .top.b -text Foo -command destroy_button
+    bind .top.b <space> destroy_button
+    pack .top.b
+    focus -force .top.b
+    update
+    event generate .top.b <space>
+    update  ; # shall not trigger error  invalid command name ".top.b"
+} -cleanup {
+    destroy .top.b .top
+} -result {} 
+
 imageFinish
 cleanupTests
 return