Added a sanity check to fix weird bug exposed when sourcing in commands from a

file with lash. Based on report from Heinz Walter.

libbb/trim.c

@@ -35,6 +35,10 @@ void trim(char *s)
 {
 	int len = strlen(s);
 
+	/* sanity check */
+	if (len == 0)
+		return;
+
 	/* trim trailing whitespace */
 	while ( len > 0 && isspace(s[len-1]))
 		s[--len]='\0';