--- trim.c	2008-08-03 11:02:17.000000000 -0400
+++ kate-trim-my-rtrim.c	2008-12-17 19:07:00.000000000 -0500
@@ -1,6 +1,7 @@
 /* $Id: trim.c 304 2008-08-03 15:02:17Z kate $ */
 
 /*
+ * originally: http://elide.org/snippets/trim.c
  * Trim whitespace.
  */
 
@@ -33,12 +34,12 @@
 char *
 rtrim(char *s) {
 	char *p = s + strlen(s) - 1;
-
+	const char *end = p;
 	while (p >= s && isspace((unsigned char) *p)) {
-		*p = '\0';
 		p--;
 	}
-
+	if (p != end)
+		*p = '\0';
 	return s;
 }