macro-stepper: don't try to remove term when at end of list

original commit: 3e77a1096fc2e4c508fd4d9abf3ccfff0e6d4a0f
2011-06-26 03:37:31 -06:00 · 2011-06-26 03:37:31 -06:00 · e0daa840aa
commit e0daa840aa
parent ae8282f5c7
1 changed files with 4 additions and 3 deletions
--- a/collects/macro-debugger/view/stepper.rkt
+++ b/collects/macro-debugger/view/stepper.rkt
@ -80,9 +80,10 @@

    ;; remove-current-term : -> void
    (define/public (remove-current-term)
-      (cursor:remove-current! terms)
-      (trim-navigator)
-      (refresh))
+      (when (cursor:has-next? terms)
+        (cursor:remove-current! terms)
+        (trim-navigator)
+        (refresh)))

    ;; show-in-new-frame : -> void
    (define/public (show-in-new-frame)