Upstream-Status: Backport

Signed-off-by: Li Xin <lixin.fnst@cn.fujitsu.com>

From https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=6c84109cfa26f35c3dfed3acb97d347361bd5849
Author: Carlos O'Donell <carlos@systemhalted.org>
Date:   Thu Oct 8 16:34:53 2015 -0400

    strcoll: Remove incorrect STRDIFF-based optimization (Bug 18589).

    The optimization introduced in commit
    f13c2a8dff2329c6692a80176262ceaaf8a6f74e, 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.

    (cherry picked from commit 87701a58e291bd7ac3b407d10a829dac52c9c16e)
---
 locale/C-collate.c           |  4 +-
 locale/categories.def        |  1 -
 locale/langinfo.h            |  1 -
 locale/localeinfo.h          |  7 ----
 locale/programs/ld-collate.c |  9 -----
 string/bug-strcoll2.c        | 95 ++++++++++++++++++++++++++++++++++++++++++++
 string/strcoll_l.c           | 39 +-----------------
 wcsmbs/wcscoll_l.c           |  1 -
 8 files changed, 98 insertions(+), 59 deletions(-)
 create mode 100644 string/bug-strcoll2.c

diff --git a/locale/C-collate.c b/locale/C-collate.c
index d7f3c55..06dfdfa 100644
--- a/locale/C-collate.c
+++ b/locale/C-collate.c
@@ -144,8 +144,6 @@ const struct __locale_data _nl_C_LC_COLLATE attribute_hidden =
     /* _NL_COLLATE_COLLSEQWC */
     { .string = (const char *) collseqwc },
     /* _NL_COLLATE_CODESET */
-    { .string = _nl_C_codeset },
-    /* _NL_COLLATE_ENCODING_TYPE */
-    { .word = __cet_8bit }
+    { .string = _nl_C_codeset }
   }
 };
diff --git a/locale/categories.def b/locale/categories.def
index 045489d..a8dda53 100644
--- a/locale/categories.def
+++ b/locale/categories.def
@@ -58,7 +58,6 @@ DEFINE_CATEGORY
   DEFINE_ELEMENT (_NL_COLLATE_COLLSEQMB,        "collate-collseqmb",        std, wstring)
   DEFINE_ELEMENT (_NL_COLLATE_COLLSEQWC,        "collate-collseqwc",        std, wstring)
   DEFINE_ELEMENT (_NL_COLLATE_CODESET,		"collate-codeset",	    std, string)
-  DEFINE_ELEMENT (_NL_COLLATE_ENCODING_TYPE,   "collate-encoding-type",    std, word)
   ), NO_POSTLOAD)
 
 
diff --git a/locale/langinfo.h b/locale/langinfo.h
index ffc5c7f..a565d9d 100644
--- a/locale/langinfo.h
+++ b/locale/langinfo.h
@@ -255,7 +255,6 @@ enum
   _NL_COLLATE_COLLSEQMB,
   _NL_COLLATE_COLLSEQWC,
   _NL_COLLATE_CODESET,
-  _NL_COLLATE_ENCODING_TYPE,
   _NL_NUM_LC_COLLATE,
 
   /* LC_CTYPE category: character classification.
diff --git a/locale/localeinfo.h b/locale/localeinfo.h
index a7516c0..c076d8e 100644
--- a/locale/localeinfo.h
+++ b/locale/localeinfo.h
@@ -110,13 +110,6 @@ enum coll_sort_rule
   sort_mask
 };
 
-/* Collation encoding type.  */
-enum collation_encoding_type
-{
-  __cet_other,
-  __cet_8bit,
-  __cet_utf8
-};
 
 /* We can map the types of the entries into a few categories.  */
 enum value_type
diff --git a/locale/programs/ld-collate.c b/locale/programs/ld-collate.c
index 16e9039..3c88c6d 100644
--- a/locale/programs/ld-collate.c
+++ b/locale/programs/ld-collate.c
@@ -32,7 +32,6 @@
 #include "linereader.h"
 #include "locfile.h"
 #include "elem-hash.h"
-#include "../localeinfo.h"
 
 /* Uncomment the following line in the production version.  */
 /* #define NDEBUG 1 */
@@ -2130,8 +2129,6 @@ collate_output (struct localedef_t *locale, const struct charmap_t *charmap,
 	  /* The words have to be handled specially.  */
 	  if (idx == _NL_ITEM_INDEX (_NL_COLLATE_SYMB_HASH_SIZEMB))
 	    add_locale_uint32 (&file, 0);
-	  else if (idx == _NL_ITEM_INDEX (_NL_COLLATE_ENCODING_TYPE))
-	    add_locale_uint32 (&file, __cet_other);
 	  else
 	    add_locale_empty (&file);
 	}
@@ -2495,12 +2492,6 @@ collate_output (struct localedef_t *locale, const struct charmap_t *charmap,
   add_locale_raw_data (&file, collate->mbseqorder, 256);
   add_locale_collseq_table (&file, &collate->wcseqorder);
   add_locale_string (&file, charmap->code_set_name);
-  if (strcmp (charmap->code_set_name, "UTF-8") == 0)
-    add_locale_uint32 (&file, __cet_utf8);
-  else if (charmap->mb_cur_max == 1)
-    add_locale_uint32 (&file, __cet_8bit);
-  else
-    add_locale_uint32 (&file, __cet_other);
   write_locale_data (output_path, LC_COLLATE, "LC_COLLATE", &file);
 
   obstack_free (&weightpool, NULL);
diff --git a/string/bug-strcoll2.c b/string/bug-strcoll2.c
new file mode 100644
index 0000000..950b090
--- /dev/null
+++ b/string/bug-strcoll2.c
@@ -0,0 +1,95 @@
+/* Bug 18589: sort-test.sh fails at random.
+ * Copyright (C) 1998-2015 Free Software Foundation, Inc.
+ * This file is part of the GNU C Library.
+ * Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
+ *
+ * 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 <stdio.h>
+#include <string.h>
+#include <locale.h>
+
+/* An incorrect strcoll optimization resulted in incorrect
+ *    results from strcoll for cs_CZ and da_DK.  */
+
+int
+test_cs_CZ (void)
+{
+  const char t1[] = "config";
+  const char t2[] = "choose";
+  if (setlocale (LC_ALL, "cs_CZ.UTF-8") == NULL)
+    {
+      perror ("setlocale");
+      return 1;
+    }
+  /* In Czech the digraph ch sorts after c, therefore we expect
+ *      config to sort before choose.  */
+  int a = strcoll (t1, t2);
+  int b = strcoll (t2, t1);
+  printf ("strcoll (\"%s\", \"%s\") = %d\n", t1, t2, a);
+  printf ("strcoll (\"%s\", \"%s\") = %d\n", t2, t1, b);
+  if (a < 0 && b > 0)
+    {
+      puts ("PASS: config < choose");
+      return 0;
+    }
+  else
+    {
+      puts ("FAIL: Wrong sorting in cz_CZ.UTF-8.");
+      return 1;
+    }
+}
+
+int
+test_da_DK (void)
+{
+  const char t1[] = "AS";
+  const char t2[] = "AA";
+  if (setlocale (LC_ALL, "da_DK.ISO-8859-1") == NULL)
+    {
+      perror ("setlocale");
+      return 1;
+    }
+  /* AA should be treated as the last letter of the Danish alphabet,
+ *      hence sorting after AS.  */
+  int a = strcoll (t1, t2);
+  int b = strcoll (t2, t1);
+  printf ("strcoll (\"%s\", \"%s\") = %d\n", t1, t2, a);
+  printf ("strcoll (\"%s\", \"%s\") = %d\n", t2, t1, b);
+  if (a < 0 && b > 0)
+    {
+      puts ("PASS: AS < AA");
+      return 0;
+    }
+  else
+    {
+      puts ("FAIL: Wrong sorting in da_DK.ISO-8859-1");
+      return 1;
+    }
+}
+
+static int
+do_test (void)
+{
+  int err = 0;
+  err |= test_cs_CZ ();
+  err |= test_da_DK ();
+  return err;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
+
+
diff --git a/string/strcoll_l.c b/string/strcoll_l.c
index b36b18c..a18b65e 100644
--- a/string/strcoll_l.c
+++ b/string/strcoll_l.c
@@ -30,7 +30,6 @@
 # define STRING_TYPE char
 # define USTRING_TYPE unsigned char
 # define STRCOLL __strcoll_l
-# define STRDIFF __strdiff
 # define STRCMP strcmp
 # define WEIGHT_H "../locale/weight.h"
 # define SUFFIX	MB
@@ -43,19 +42,6 @@
 #include "../locale/localeinfo.h"
 #include WEIGHT_H
 
-#define MASK_UTF8_7BIT  (1 << 7)
-#define MASK_UTF8_START (3 << 6)
-
-size_t
-STRDIFF (const STRING_TYPE *s, const STRING_TYPE *t)
-{
-  size_t n;
-
-  for (n = 0; *s != '\0' && *s++ == *t++; ++n)
-    continue;
-
-  return n;
-}
 
 /* Track status while looking for sequences in a string.  */
 typedef struct
@@ -274,29 +260,9 @@ STRCOLL (const STRING_TYPE *s1, const STRING_TYPE *s2, __locale_t l)
   const USTRING_TYPE *extra;
   const int32_t *indirect;
 
-  /* In case there is no locale specific sort order (C / POSIX).  */
   if (nrules == 0)
     return STRCMP (s1, s2);
 
-  /* Fast forward to the position of the first difference.  Needs to be
-     encoding aware as the byte-by-byte comparison can stop in the middle
-     of a char sequence for multibyte encodings like UTF-8.  */
-  uint_fast32_t encoding =
-    current->values[_NL_ITEM_INDEX (_NL_COLLATE_ENCODING_TYPE)].word;
-  if (encoding != __cet_other)
-    {
-      size_t diff = STRDIFF (s1, s2);
-      if (diff > 0)
-	{
-	  if (encoding == __cet_utf8 && (*(s1 + diff) & MASK_UTF8_7BIT) != 0)
-	    do
-	      diff--;
-	    while (diff > 0 && (*(s1 + diff) & MASK_UTF8_START) != MASK_UTF8_START);
-	  s1 += diff;
-	  s2 += diff;
-	}
-    }
-
   /* Catch empty strings.  */
   if (__glibc_unlikely (*s1 == '\0') || __glibc_unlikely (*s2 == '\0'))
     return (*s1 != '\0') - (*s2 != '\0');
@@ -363,9 +329,8 @@ STRCOLL (const STRING_TYPE *s1, const STRING_TYPE *s2, __locale_t l)
 		     byte-level comparison to ensure that we don't waste time
 		     going through multiple passes for totally equal strings
 		     before proceeding to subsequent passes.  */
-		  if (pass == 0 && encoding == __cet_other &&
-		      STRCMP (s1, s2) == 0)
-		    return result;
+		  if (pass == 0 && STRCMP (s1, s2) == 0)
+                    return result;
 		  else
 		    break;
 	        }
diff --git a/wcsmbs/wcscoll_l.c b/wcsmbs/wcscoll_l.c
index 6d9384a..87f240d 100644
--- a/wcsmbs/wcscoll_l.c
+++ b/wcsmbs/wcscoll_l.c
@@ -23,7 +23,6 @@
 #define STRING_TYPE wchar_t
 #define USTRING_TYPE wint_t
 #define STRCOLL __wcscoll_l
-#define STRDIFF __wcsdiff
 #define STRCMP __wcscmp
 #define WEIGHT_H "../locale/weightwc.h"
 #define SUFFIX	WC
-- 
1.8.4.2