From: Alejandro Colomar <alx.manpages@gmail.com>
Date: Wed, 28 Jul 2021 20:20:03 +0000 (+0200)
Subject: strstr.3: Document special case for empty needle
X-Git-Tag: man-pages-5.13~157
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ec415ad9705fe642d00ea8aa7abcb2f4b47992bd;p=thirdparty%2Fman-pages.git

strstr.3: Document special case for empty needle

Reported-by: Stefan Kanthak <stefan.kanthak@nexgo.de>
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
---

diff --git a/man3/strstr.3 b/man3/strstr.3
index e085409c27..41ee874892 100644
--- a/man3/strstr.3
+++ b/man3/strstr.3
@@ -61,6 +61,14 @@ but ignores the case of both arguments.
 .SH RETURN VALUE
 These functions return a pointer to the beginning of the
 located substring, or NULL if the substring is not found.
+.PP
+Note the special case:
+If
+.I needle
+is the empty string,
+the return value is always
+.I haystack
+itself.
 .SH ATTRIBUTES
 For an explanation of the terms used in this section, see
 .BR attributes (7).