only when when there is something to undo

rfindler · rmculpepper · commit f640c2cea01d · 2013-01-28T13:14:36.000-05:00
They hypothesis behind this change is that the undo is undoing an edit that came before, not the temporary edit that appears in insert-close-paren. So, when there are no edits happening (ie when fixup? is #f) then don't undo. This is only a hypothesis because we were not able to find a small code sequence, outside of DrRacket to cause the bad behavior, so possibly there is really more going on here. Thanks to Nadeem Abdul Hamid for finding this fix. Closes PR 13454 (cherry picked from commit f90eb33)
diff --git a/collects/framework/private/color.rkt b/collects/framework/private/color.rkt
@@ -1075,7 +1075,7 @@ added get-regions
            (cond
              [(eq? smart-skip 'adjacent)
               (end-edit-sequence)  ;; wraps up the net-zero editing changes done by get-close-paren etc.
-              (undo)               ;; to avoid messing up the editor's modified state in case of a simple skip
+              (when fixup? (undo)) ;; to avoid messing up the editor's modified state in case of a simple skip
               (if (and next-close-start next-close-adj?
                        (string=? insert-str next-close-str))
                   (skip next-close-end)
