test for renaming lexical subs

[p5sagit/Sub-Name.git] / Name.xs

diff --git a/Name.xs b/Name.xs
index 3484085..9a4d493 100644 (file)
--- a/Name.xs
+++ b/Name.xs
@@ -63,13 +63,13 @@ subname(name, sub)
                croak("Not a subroutine reference");
 
        for (s = nameptr; s <= nameptr + namelen; s++) {
-               if (*s == ':' && s[-1] == ':') {
+               if (s > nameptr && *s == ':' && s[-1] == ':') {
                        end = s - 1;
                        begin = ++s;
                        if (seen_quote)
                                need_subst++;
                }
-               else if (*s && s[-1] == '\'') {
+               else if (s > nameptr && *s != '\0' && s[-1] == '\'') {
                        end = s - 1;
                        begin = s;
                        if (seen_quote++)