diff -ur php5-200309180130.orig/ext/mbstring/php_mbregex.c php5-200309180130/ext/mbstring/php_mbregex.c
--- php5-200309180130.orig/ext/mbstring/php_mbregex.c	Sat Aug 23 16:07:41 2003
+++ php5-200309180130/ext/mbstring/php_mbregex.c	Mon Sep 22 00:36:52 2003
@@ -653,7 +653,12 @@
 			}
 		} else { /* nomatch */
 			/* stick that last bit of string on our output */
-			smart_str_appendl(&out_buf, pos, (size_t)((UChar *)(string + string_len) - pos));
+			int l = (UChar *)(string + string_len) - pos;
+			if (l > 0) {
+				smart_str_appendl(&out_buf, pos, l);
+			} else {
+				out_buf.len += l;
+			}
 		}
 		php_mb_regex_region_free(regs, 0);
 	}