stacktrace: handle missing cmd in [info frame]

Some stack frames may have no cmd (e.g. with eval).
Ensure that [stacktrace] still handles such frames by setting an
empty proc name in that case.

Signed-off-by: Steve Bennett <steveb@workware.net.au>

1 files changed, 1 insertions, 1 deletions

diff --git a/stdlib.tcl b/stdlib.tcl
index 01d73c0..cd82419 100644
--- a/stdlib.tcl
+++ b/stdlib.tcl
@@ -42,7 +42,7 @@ proc stacktrace {{skip 0}} {
 	incr skip 2
 	loop level $skip [info level]+1 {
 		set frame [info frame -$level]
-		lappend trace [lindex [dict get $frame cmd] 0] [dict get $frame file] [dict get $frame line]
+		lappend trace [lindex [dict getdef $frame cmd {}] 0] [dict get $frame file] [dict get $frame line]
 	}
 	return $trace
 }