--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2005-08-16  Bruno Haible  <bruno@clisp.org>
+
+	* modules/strcase (Files): Add m4/mbrtowc.m4.
+	(Depends-on): Add strnlen1, mbchar.
+
 2005-08-16  Bruno Haible  <bruno@clisp.org>
 
 	* modules/strnlen1: New file.

--- a/lib/ChangeLog
+++ b/lib/ChangeLog
@@ -1,3 +1,10 @@
+2005-08-16  Bruno Haible  <bruno@clisp.org>
+
+	* strcase.h (strcasecmp): Add note in comments.
+	* strncasecmp.c: Use code from strcasecmp.c.
+	* strcasecmp.c: Use mbchar module. Define private mbiter variant.
+	(strcasecmp): Work correctly in multibyte locales.
+
 2005-08-16  Bruno Haible  <bruno@clisp.org>
 
 	* strnlen1.h: New file.

--- a/lib/strcase.h
+++ b/lib/strcase.h
@@ -1,5 +1,5 @@
 /* Case-insensitive string comparison functions.
-   Copyright (C) 1995-1996, 2001, 2003 Free Software Foundation, Inc.
+   Copyright (C) 1995-1996, 2001, 2003, 2005 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -29,7 +29,8 @@
 /* Compare strings S1 and S2, ignoring case, returning less than, equal to or
    greater than zero if S1 is lexicographically less than, equal to or greater
    than S2.
-   Note: This function does not work correctly in multibyte locales.  */
+   Note: This function may, in multibyte locales, return 0 for strings of
+   different lengths!  */
 extern int strcasecmp (const char *s1, const char *s2);
 
 /* Compare no more than N characters of strings S1 and S2, ignoring case,

--- a/lib/strcasecmp.c
+++ b/lib/strcasecmp.c
@@ -1,5 +1,7 @@
-/* strcasecmp.c -- case insensitive string comparator
-   Copyright (C) 1998, 1999 Free Software Foundation, Inc.
+/* Case-insensitive string comparison function.
+   Copyright (C) 1998, 1999, 2005 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2005,
+   based on earlier glibc code.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -15,52 +17,225 @@
    along with this program; if not, write to the Free Software Foundation,
    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
 
-#if HAVE_CONFIG_H
+#ifdef HAVE_CONFIG_H
 # include <config.h>
 #endif
 
-#ifdef LENGTH_LIMIT
-# define STRXCASECMP_FUNCTION strncasecmp
-# define STRXCASECMP_DECLARE_N , size_t n
-# define LENGTH_LIMIT_EXPR(Expr) Expr
-#else
-# define STRXCASECMP_FUNCTION strcasecmp
-# define STRXCASECMP_DECLARE_N /* empty */
-# define LENGTH_LIMIT_EXPR(Expr) 0
+/* Specification.  */
+#include "strcase.h"
+
+#include <ctype.h>
+
+#if HAVE_MBRTOWC
+
+#include "strnlen1.h"
+
+/* Like mbiter.h, except it doesn't look at the entire string.  */
+
+#include "mbchar.h"
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <wchar.h>
+#include <wctype.h>
+
+struct mbiter_multi
+{
+  bool at_end;		/* true if the end of the string has been reached */
+  bool in_shift;	/* true if next byte may not be interpreted as ASCII */
+  mbstate_t state;	/* if in_shift: current shift state */
+  bool next_done;	/* true if mbi_avail has already filled the following */
+  struct mbchar cur;	/* the current character:
+	const char *cur.ptr		pointer to current character
+	The following are only valid after mbi_avail.
+	size_t cur.bytes		number of bytes of current character
+	bool cur.wc_valid		true if wc is a valid wide character
+	wchar_t cur.wc			if wc_valid: the current character
+	*/
+};
+
+static inline void
+mbiter_multi_next (struct mbiter_multi *iter)
+{
+  if (iter->next_done)
+    return;
+  if (iter->in_shift)
+    goto with_shift;
+  /* Handle most ASCII characters quickly, without calling mbrtowc().  */
+  if (is_basic (*iter->cur.ptr))
+    {
+      /* These characters are part of the basic character set.  ISO C 99
+	 guarantees that their wide character code is identical to their
+	 char code.  */
+      iter->cur.bytes = 1;
+      iter->cur.wc = *iter->cur.ptr;
+      iter->cur.wc_valid = true;
+    }
+  else
+    {
+      assert (mbsinit (&iter->state));
+      iter->in_shift = true;
+    with_shift:
+      iter->cur.bytes = mbrtowc (&iter->cur.wc, iter->cur.ptr,
+				 strnlen1 (iter->cur.ptr, MB_CUR_MAX),
+				 &iter->state);
+      if (iter->cur.bytes == (size_t) -1)
+	{
+	  /* An invalid multibyte sequence was encountered.  */
+	  iter->cur.bytes = 1;
+	  iter->cur.wc_valid = false;
+	  /* Whether to set iter->in_shift = false and reset iter->state
+	     or not is not very important; the string is bogus anyway.  */
+	}
+      else if (iter->cur.bytes == (size_t) -2)
+	{
+	  /* An incomplete multibyte character at the end.  */
+	  iter->cur.bytes = strlen (iter->cur.ptr) + 1;
+	  iter->cur.wc_valid = false;
+	  /* Whether to set iter->in_shift = false and reset iter->state
+	     or not is not important; the string end is reached anyway.  */
+	}
+      else
+	{
+	  if (iter->cur.bytes == 0)
+	    {
+	      /* A null wide character was encountered.  */
+	      iter->cur.bytes = 1;
+	      assert (*iter->cur.ptr == '\0');
+	      assert (iter->cur.wc == 0);
+	    }
+	  iter->cur.wc_valid = true;
+
+	  /* When in the initial state, we can go back treating ASCII
+	     characters more quickly.  */
+	  if (mbsinit (&iter->state))
+	    iter->in_shift = false;
+	}
+    }
+  iter->next_done = true;
+}
+
+static inline void
+mbiter_multi_reloc (struct mbiter_multi *iter, ptrdiff_t ptrdiff)
+{
+  iter->cur.ptr += ptrdiff;
+}
+
+/* Iteration macros.  */
+typedef struct mbiter_multi mbi_iterator_t;
+#define mbi_init(iter, startptr) \
+  ((iter).cur.ptr = (startptr), (iter).at_end = false, \
+   (iter).in_shift = false, memset (&(iter).state, '\0', sizeof (mbstate_t)), \
+   (iter).next_done = false)
+#define mbi_avail(iter) \
+  (!(iter).at_end && (mbiter_multi_next (&(iter)), true))
+#define mbi_advance(iter) \
+  ((mb_isnul ((iter).cur) ? ((iter).at_end = true) : 0), \
+   (iter).cur.ptr += (iter).cur.bytes, (iter).next_done = false)
+
+/* Access to the current character.  */
+#define mbi_cur(iter) (iter).cur
+#define mbi_cur_ptr(iter) (iter).cur.ptr
+
 #endif
 
-#include <stddef.h>
-#include <ctype.h>
-
 #define TOLOWER(Ch) (isupper (Ch) ? tolower (Ch) : (Ch))
 
-/* Compare {{no more than N characters of }}strings S1 and S2,
-   ignoring case, returning less than, equal to or
-   greater than zero if S1 is lexicographically less
-   than, equal to or greater than S2.  */
-
+/* Compare strings S1 and S2, ignoring case, returning less than, equal to or
+   greater than zero if S1 is lexicographically less than, equal to or greater
+   than S2.
+   Note: This function may, in multibyte locales, return 0 for strings of
+   different lengths!  */
 int
-STRXCASECMP_FUNCTION (const char *s1, const char *s2 STRXCASECMP_DECLARE_N)
+strcasecmp (const char *s1, const char *s2)
 {
-  register const unsigned char *p1 = (const unsigned char *) s1;
-  register const unsigned char *p2 = (const unsigned char *) s2;
-  unsigned char c1, c2;
-
-  if (p1 == p2 || LENGTH_LIMIT_EXPR (n == 0))
+  if (s1 == s2)
     return 0;
 
-  do
+  /* Be careful not to look at the entire extent of s1 or s2 until needed.
+     This is useful because when two strings differ, the difference is
+     most often already in the very few first characters.  */
+#if HAVE_MBRTOWC
+  if (MB_CUR_MAX > 1)
     {
-      c1 = TOLOWER (*p1);
-      c2 = TOLOWER (*p2);
+      mbi_iterator_t iter1;
+      mbi_iterator_t iter2;
+
+      mbi_init (iter1, s1);
+      mbi_init (iter2, s2);
 
-      if (LENGTH_LIMIT_EXPR (--n == 0) || c1 == '\0')
-	break;
+      while (mbi_avail (iter1) && mbi_avail (iter2))
+	{
+	  /* Sort invalid characters after all valid ones.  */
+	  if (!mbi_cur (iter1).wc_valid)
+	    {
+	      if (!mbi_cur (iter2).wc_valid)
+		{
+		  /* Compare two invalid characters.  */
+		  int cmp;
 
-      ++p1;
-      ++p2;
+		  if (mbi_cur (iter1).bytes > mbi_cur (iter2).bytes)
+		    return 1;
+		  if (mbi_cur (iter1).bytes < mbi_cur (iter2).bytes)
+		    return -1;
+		  cmp = memcmp (mbi_cur_ptr (iter1), mbi_cur_ptr (iter2),
+				mbi_cur (iter1).bytes);
+		  if (cmp != 0)
+		    return cmp;
+		}
+	      else
+		/* mbi_cur (iter1) invalid, mbi_cur (iter2) valid.  */
+		return 1;
+	    }
+	  else
+	    {
+	      if (!mbi_cur (iter2).wc_valid)
+		/* mbi_cur (iter1) valid, mbi_cur (iter2) invalid.  */
+		return -1;
+	      else
+		{
+		  /* Compare two valid characters.  */
+		  wchar_t c1 = towlower (mbi_cur (iter1).wc);
+		  wchar_t c2 = towlower (mbi_cur (iter2).wc);
+
+		  if (c1 > c2)
+		    return 1;
+		  if (c1 < c2)
+		    return -1;
+		}
+	    }
+	  mbi_advance (iter1);
+	  mbi_advance (iter2);
+	}
+      if (mbi_avail (iter1))
+	/* s2 terminated before s1.  */
+	return 1;
+      if (mbi_avail (iter2))
+	/* s1 terminated before s2.  */
+	return -1;
+      return 0;
     }
-  while (c1 == c2);
+  else
+#endif
+    {
+      const unsigned char *p1 = (const unsigned char *) s1;
+      const unsigned char *p2 = (const unsigned char *) s2;
+      unsigned char c1, c2;
+
+      do
+	{
+	  c1 = TOLOWER (*p1);
+	  c2 = TOLOWER (*p2);
 
-  return c1 - c2;
+	  if (c1 == '\0')
+	    break;
+
+	  ++p1;
+	  ++p2;
+	}
+      while (c1 == c2);
+
+      return c1 - c2;
+    }
 }

--- a/lib/strncasecmp.c
+++ b/lib/strncasecmp.c
@@ -1,2 +1,58 @@
-#define LENGTH_LIMIT
-#include "strcasecmp.c"
+/* strncasecmp.c -- case insensitive string comparator
+   Copyright (C) 1998, 1999 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+/* Specification.  */
+#include "strcase.h"
+
+#include <ctype.h>
+
+#define TOLOWER(Ch) (isupper (Ch) ? tolower (Ch) : (Ch))
+
+/* Compare no more than N bytes of strings S1 and S2,
+   ignoring case, returning less than, equal to or
+   greater than zero if S1 is lexicographically less
+   than, equal to or greater than S2.  */
+
+int
+strncasecmp (const char *s1, const char *s2, size_t n)
+{
+  register const unsigned char *p1 = (const unsigned char *) s1;
+  register const unsigned char *p2 = (const unsigned char *) s2;
+  unsigned char c1, c2;
+
+  if (p1 == p2 || n == 0)
+    return 0;
+
+  do
+    {
+      c1 = TOLOWER (*p1);
+      c2 = TOLOWER (*p2);
+
+      if (--n == 0 || c1 == '\0')
+	break;
+
+      ++p1;
+      ++p2;
+    }
+  while (c1 == c2);
+
+  return c1 - c2;
+}

--- a/m4/ChangeLog
+++ b/m4/ChangeLog
@@ -1,3 +1,8 @@
+2005-08-16  Bruno Haible  <bruno@clisp.org>
+
+	* strcase.m4 (gl_FUNC_STRCASECMP): Use the replacement function always.
+	(gl_PREREQ_STRCASECMP): Use gl_FUNC_MBRTOWC.
+
 2005-08-16  Bruno Haible  <bruno@clisp.org>
 
 	* mbfile.m4: New file.

--- a/m4/strcase.m4
+++ b/m4/strcase.m4
@@ -1,5 +1,5 @@
-# strcase.m4 serial 1
-dnl Copyright (C) 2002 Free Software Foundation, Inc.
+# strcase.m4 serial 2
+dnl Copyright (C) 2002, 2005 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -12,10 +12,11 @@
 
 AC_DEFUN([gl_FUNC_STRCASECMP],
 [
-  AC_REPLACE_FUNCS(strcasecmp)
-  if test $ac_cv_func_strcasecmp = no; then
-    gl_PREREQ_STRCASECMP
-  fi
+  dnl No known system has a strcasecmp() function that works correctly in
+  dnl multibyte locales. Therefore we use our version always.
+  AC_LIBOBJ(strcasecmp)
+  AC_DEFINE(strcasecmp, rpl_strcasecmp, [Define to rpl_strcasecmp always.])
+  gl_PREREQ_STRCASECMP
 ])
 
 AC_DEFUN([gl_FUNC_STRNCASECMP],
@@ -28,7 +29,7 @@
 
 # Prerequisites of lib/strcasecmp.c.
 AC_DEFUN([gl_PREREQ_STRCASECMP], [
-  :
+  gl_FUNC_MBRTOWC
 ])
 
 # Prerequisites of lib/strncasecmp.c.

--- a/modules/strcase
+++ b/modules/strcase
@@ -6,8 +6,11 @@
 lib/strcasecmp.c
 lib/strncasecmp.c
 m4/strcase.m4
+m4/mbrtowc.m4
 
 Depends-on:
+strnlen1
+mbchar
 
 configure.ac:
 gl_STRCASE