From 1a51193899293367201e0698ce08a94f404f059a Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Thu, 2 Apr 2026 08:45:35 +0000
Subject: [PATCH] Handle empty regular expression in substitution, found by
 ossfuzz.

---
 regsub.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/regsub.c b/regsub.c
index 61a9c324..91be3994 100644
--- a/regsub.c
+++ b/regsub.c
@@ -68,6 +68,8 @@ regsub(const char *pattern, const char *with, const char *text, int flags)
 
 	if (*text == '\0')
 		return (xstrdup(""));
+	if (*pattern == '\0')
+		return (xstrdup(text));
 	if (regcomp(&r, pattern, flags) != 0)
 		return (NULL);