glibc/wcsmbs/wcscoll_l.c
Carlos O'Donell 87701a58e2 strcoll: Remove incorrect STRDIFF-based optimization (Bug 18589).
The optimization introduced in commit
f13c2a8dff, causes regressions in
sorting for languages that have digraphs that change sort order, like
cs_CZ which sorts ch between h and i.

My analysis shows the fast-forwarding optimization in STRCOLL advances
through a digraph while possibly stopping in the middle which results
in a subsequent skipping of the digraph and incorrect sorting. The
optimization is incorrect as implemented and because of that I'm
removing it for 2.23, and I will also commit this fix for 2.22 where
it was originally introduced.

This patch reverts the optimization, introduces a new bug-strcoll2.c
regression test that tests both cs_CZ.UTF-8 and da_DK.ISO-8859-1 and
ensures they sort one digraph each correctly. The optimization can't be
applied without regressing this test.

Checked on x86_64, bug-strcoll2.c fails without this patch and passes
after. This will also get a fix on 2.22 which has the same bug.
2015-10-08 16:41:45 -04:00

35 lines
1.2 KiB
C

/* Copyright (C) 1996-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1996.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <wchar.h>
#include "../locale/coll-lookup.h"
#define STRING_TYPE wchar_t
#define USTRING_TYPE wint_t
#define STRCOLL __wcscoll_l
#define STRCMP __wcscmp
#define WEIGHT_H "../locale/weightwc.h"
#define SUFFIX WC
#define L(arg) L##arg
#define WIDE_CHAR_VERSION 1
#include "../string/strcoll_l.c"
weak_alias (__wcscoll_l, wcscoll_l)