Date: Thu, 9 Feb 2017 21:23:42 +0000 (UTC) From: Ngie Cooper <ngie@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r313480 - in stable/10: contrib/netbsd-tests/lib/libc/string lib/libc/string Message-ID: <201702092123.v19LNg0P071867@repo.freebsd.org>
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Author: ngie Date: Thu Feb 9 21:23:41 2017 New Revision: 313480 URL: https://svnweb.freebsd.org/changeset/base/313480 Log: MFC r283584: Relnotes: yes r283584 (by emaste): memmem(3): empty little string matches the beginning of the big string This function originated in glibc, and this matches their behaviour (and NetBSD, OpenBSD, and musl). An empty big string (arg "l") is handled by the existing l_len < s_len test. Modified: stable/10/contrib/netbsd-tests/lib/libc/string/t_memmem.c stable/10/lib/libc/string/memmem.3 stable/10/lib/libc/string/memmem.c Directory Properties: stable/10/ (props changed) Modified: stable/10/contrib/netbsd-tests/lib/libc/string/t_memmem.c ============================================================================== --- stable/10/contrib/netbsd-tests/lib/libc/string/t_memmem.c Thu Feb 9 21:19:24 2017 (r313479) +++ stable/10/contrib/netbsd-tests/lib/libc/string/t_memmem.c Thu Feb 9 21:23:41 2017 (r313480) @@ -75,7 +75,7 @@ ATF_TC_HEAD(memmem_basic, tc) ATF_TC_BODY(memmem_basic, tc) { -#if defined(__darwin__) || defined(__FreeBSD__) +#if defined(__darwin__) expect(memmem(b2, lb2, p0, lp0) == NULL); expect(memmem(b0, lb0, p0, lp0) == NULL); #else Modified: stable/10/lib/libc/string/memmem.3 ============================================================================== --- stable/10/lib/libc/string/memmem.3 Thu Feb 9 21:19:24 2017 (r313479) +++ stable/10/lib/libc/string/memmem.3 Thu Feb 9 21:23:41 2017 (r313480) @@ -26,7 +26,7 @@ .\" .\" $FreeBSD$ .\" -.Dd August 24, 2005 +.Dd May 26, 2015 .Dt MEMMEM 3 .Os .Sh NAME @@ -51,14 +51,12 @@ in the byte string .Fa big . .Sh RETURN VALUES If -.Fa big_len -is smaller than -.Fa little_len , -if .Fa little_len -is 0, if -.Fa big_len -is 0 or if +is zero +.Fa big +is returned (that is, an empty little is deemed to match at the beginning of +big); +if .Fa little occurs nowhere in .Fa big , @@ -84,3 +82,11 @@ function first appeared in .Sh BUGS This function was broken in Linux libc up to and including version 5.0.9 and in GNU libc prior to version 2.1. +Prior to +.Fx 11.0 +.Nm +returned +.Dv NULL +when +.Fa little_len +equals 0. Modified: stable/10/lib/libc/string/memmem.c ============================================================================== --- stable/10/lib/libc/string/memmem.c Thu Feb 9 21:19:24 2017 (r313479) +++ stable/10/lib/libc/string/memmem.c Thu Feb 9 21:23:41 2017 (r313480) @@ -42,9 +42,9 @@ memmem(const void *l, size_t l_len, cons const char *cl = (const char *)l; const char *cs = (const char *)s; - /* we need something to compare */ - if (l_len == 0 || s_len == 0) - return NULL; + /* empty "s" matches the beginning of "l" */ + if (s_len == 0) + return (void *)cl; /* "s" must be smaller or equal to "l" */ if (l_len < s_len)
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