coreutils/coreutils-i18n-expand-unexpand.patch

From 332e9adf944e4ea232a855b1bf75ea4ddfd7e794 Mon Sep 17 00:00:00 2001
From: Ondrej Oprala <ooprala@redhat.com>
Date: Wed, 5 Aug 2015 09:15:09 +0200
Subject: [PATCH] expand,unexpand: add multibyte support
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

* NEWS: Mention the changes.
* bootstrap.conf: Add mbfile to the list of modules.
* configure.ac: Properly initialize mbfile.
* po/POTFILES.in: Add new source file.
* src/expand-core.c: Move functions common to both expand and
unexpand to this file.
* src/expand-core.h: Add function prototypes from expand-core.c.
* src/expand.c (expand): Iterate over multibyte characters properly.
* src/local.mk: Add expand-core.c to the lists of source codes for
expand and unexpand
* src/unexpand.c (unexpand): Iterate over multibyte characters
properly.
* tests/local.mk: Add new tests.
* tests/{expand,unexpand}/mb.sh: New tests.

Co-authored-by: Pádraig Brady <pbrady@redhat.com>
---
 bootstrap.conf       |   1 +
 configure.ac         |   2 +
 lib/mbfile.c         |   3 +
 lib/mbfile.h         | 255 +++++++++++++++++++++++++++++++++++++++++++++++++++
 m4/mbfile.m4         |  14 +++
 po/POTFILES.in       |   1 +
 src/expand-core.c    | 150 ++++++++++++++++++++++++++++++
 src/expand-core.h    |  41 +++++++++
 src/expand.c         | 186 ++++++++-----------------------------
 src/local.mk         |   2 +
 src/unexpand.c       | 195 ++++++++++-----------------------------
 tests/expand/mb.sh   |  98 ++++++++++++++++++++
 tests/local.mk       |   2 +
 tests/unexpand/mb.sh |  97 ++++++++++++++++++++
 14 files changed, 750 insertions(+), 297 deletions(-)
 create mode 100644 lib/mbfile.c
 create mode 100644 lib/mbfile.h
 create mode 100644 m4/mbfile.m4
 create mode 100644 src/expand-core.c
 create mode 100644 src/expand-core.h
 create mode 100755 tests/expand/mb.sh
 create mode 100755 tests/unexpand/mb.sh

diff --git a/bootstrap.conf b/bootstrap.conf
index ef1c078..ea8cebc 100644
--- a/bootstrap.conf
+++ b/bootstrap.conf
@@ -151,6 +151,7 @@ gnulib_modules="
   maintainer-makefile
   malloc-gnu
   manywarnings
+  mbfile
   mbrlen
   mbrtowc
   mbsalign
diff --git a/configure.ac b/configure.ac
index 8dc2192..b8b5114 100644
--- a/configure.ac
+++ b/configure.ac
@@ -425,6 +425,8 @@ fi
 # I'm leaving it here for now.  This whole thing needs to be modernized...
 gl_WINSIZE_IN_PTEM
 
+gl_MBFILE
+
 gl_HEADER_TIOCGWINSZ_IN_TERMIOS_H
 
 if test $gl_cv_sys_tiocgwinsz_needs_termios_h = no && \
diff --git a/po/POTFILES.in b/po/POTFILES.in
index b3fe668..c594d20 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -57,6 +57,7 @@ src/dirname.c
 src/du.c
 src/echo.c
 src/env.c
+src/expand-core.c
 src/expand.c
 src/expr.c
 src/factor.c
diff --git a/src/expand-core.c b/src/expand-core.c
new file mode 100644
index 0000000..c8445db
--- /dev/null
+++ b/src/expand-core.c
@@ -0,0 +1,150 @@
+/* expand-core.c - elementary functions for the expand and unexpand utilities
+   Copyright (C) 1989-2015 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 3 of the License, 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, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <sys/types.h>
+
+#include "system.h"
+#include "error.h"
+#include "fadvise.h"
+#include "quote.h"
+#include "xstrndup.h"
+
+#include "expand-core.h"
+
+/* Add the comma or blank separated list of tab stops STOPS
+   to the list of tab stops.  */
+
+extern void
+parse_tab_stops (char const *stops, void (*add_tab_stop)(uintmax_t))
+{
+  bool have_tabval = false;
+  uintmax_t tabval IF_LINT ( = 0);
+  char const *num_start IF_LINT ( = NULL);
+  bool ok = true;
+
+  for (; *stops; stops++)
+    {
+      if (*stops == ',' || isblank (to_uchar (*stops)))
+        {
+          if (have_tabval)
+            add_tab_stop (tabval);
+          have_tabval = false;
+        }
+      else if (ISDIGIT (*stops))
+        {
+          if (!have_tabval)
+            {
+              tabval = 0;
+              have_tabval = true;
+              num_start = stops;
+            }
+
+          /* Detect overflow.  */
+          if (!DECIMAL_DIGIT_ACCUMULATE (tabval, *stops - '0', uintmax_t))
+            {
+              size_t len = strspn (num_start, "0123456789");
+              char *bad_num = xstrndup (num_start, len);
+              error (0, 0, _("tab stop is too large %s"), quote (bad_num));
+              free (bad_num);
+              ok = false;
+              stops = num_start + len - 1;
+            }
+        }
+      else
+        {
+          error (0, 0, _("tab size contains invalid character(s): %s"),
+                 quote (stops));
+          ok = false;
+          break;
+        }
+    }
+
+  if (!ok)
+    exit (EXIT_FAILURE);
+
+  if (have_tabval)
+    add_tab_stop (tabval);
+}
+
+/* Check that the list of tab stops TABS, with ENTRIES entries,
+   contains only nonzero, ascending values.  */
+
+extern void
+validate_tab_stops (uintmax_t const *tabs, size_t entries)
+{
+  uintmax_t prev_tab = 0;
+  size_t i;
+
+  for (i = 0; i < entries; i++)
+    {
+      if (tabs[i] == 0)
+        error (EXIT_FAILURE, 0, _("tab size cannot be 0"));
+      if (tabs[i] <= prev_tab)
+        error (EXIT_FAILURE, 0, _("tab sizes must be ascending"));
+      prev_tab = tabs[i];
+    }
+}
+
+/* Close the old stream pointer FP if it is non-NULL,
+   and return a new one opened to read the next input file.
+   Open a filename of '-' as the standard input.
+   Return NULL if there are no more input files.  */
+
+extern FILE *
+next_file (FILE *fp)
+{
+  static char *prev_file;
+  char *file;
+
+  if (fp)
+    {
+      if (ferror (fp))
+        {
+          error (0, errno, "%s", prev_file);
+          exit_status = EXIT_FAILURE;
+        }
+      if (STREQ (prev_file, "-"))
+        clearerr (fp);		/* Also clear EOF.  */
+      else if (fclose (fp) != 0)
+        {
+          error (0, errno, "%s", prev_file);
+          exit_status = EXIT_FAILURE;
+        }
+    }
+
+  while ((file = *file_list++) != NULL)
+    {
+      if (STREQ (file, "-"))
+        {
+          have_read_stdin = true;
+          fp = stdin;
+        }
+      else
+        fp = fopen (file, "r");
+      if (fp)
+        {
+          prev_file = file;
+          fadvise (fp, FADVISE_SEQUENTIAL);
+          return fp;
+        }
+      error (0, errno, "%s", file);
+      exit_status = EXIT_FAILURE;
+    }
+  return NULL;
+}
diff --git a/src/expand-core.h b/src/expand-core.h
new file mode 100644
index 0000000..2419407
--- /dev/null
+++ b/src/expand-core.h
@@ -0,0 +1,41 @@
+/* expand-core.h - function prototypes for the expand and unexpand utilities
+   Copyright (C) 1989-2015 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 3 of the License, 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, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef EXPAND_CORE_H_
+# define EXPAND_CORE_H_
+
+extern size_t first_free_tab;
+
+extern size_t n_tabs_allocated;
+
+extern uintmax_t *tab_list;
+
+extern int exit_status;
+
+extern char **file_list;
+
+extern bool have_read_stdin;
+
+void
+parse_tab_stops (char const *stops, void (*add_tab_stop)(uintmax_t));
+
+void
+validate_tab_stops (uintmax_t const *tabs, size_t entries);
+
+FILE *
+next_file (FILE *fp);
+
+#endif /* EXPAND_CORE_H_ */
diff --git a/src/expand.c b/src/expand.c
index 0a40a1a..ed97fd4 100644
--- a/src/expand.c
+++ b/src/expand.c
@@ -37,12 +37,16 @@
 #include <stdio.h>
 #include <getopt.h>
 #include <sys/types.h>
+
+#include <mbfile.h>
+
 #include "system.h"
 #include "error.h"
 #include "fadvise.h"
-#include "quote.h"
 #include "xstrndup.h"
 
+#include "expand-core.h"
+
 /* The official name of this program (e.g., no 'g' prefix).  */
 #define PROGRAM_NAME "expand"
 
@@ -58,17 +62,17 @@ static uintmax_t tab_size;
 /* Array of the explicit column numbers of the tab stops;
    after 'tab_list' is exhausted, each additional tab is replaced
    by a space.  The first column is column 0.  */
-static uintmax_t *tab_list;
+uintmax_t *tab_list;
 
 /* The number of allocated entries in 'tab_list'.  */
-static size_t n_tabs_allocated;
+size_t n_tabs_allocated;
 
 /* The index of the first invalid element of 'tab_list',
    where the next element can be added.  */
-static size_t first_free_tab;
+size_t first_free_tab;
 
 /* Null-terminated array of input filenames.  */
-static char **file_list;
+char **file_list;
 
 /* Default for 'file_list' if no files are given on the command line.  */
 static char *stdin_argv[] =
@@ -77,10 +81,10 @@ static char *stdin_argv[] =
 };
 
 /* True if we have ever read standard input.  */
-static bool have_read_stdin;
+bool have_read_stdin;
 
 /* The desired exit status.  */
-static int exit_status;
+int exit_status;
 
 static char const shortopts[] = "it:0::1::2::3::4::5::6::7::8::9::";
 
@@ -135,128 +139,6 @@ add_tab_stop (uintmax_t tabval)
   tab_list[first_free_tab++] = tabval;
 }
 
-/* Add the comma or blank separated list of tab stops STOPS
-   to the list of tab stops.  */
-
-static void
-parse_tab_stops (char const *stops)
-{
-  bool have_tabval = false;
-  uintmax_t tabval IF_LINT ( = 0);
-  char const *num_start IF_LINT ( = NULL);
-  bool ok = true;
-
-  for (; *stops; stops++)
-    {
-      if (*stops == ',' || isblank (to_uchar (*stops)))
-        {
-          if (have_tabval)
-            add_tab_stop (tabval);
-          have_tabval = false;
-        }
-      else if (ISDIGIT (*stops))
-        {
-          if (!have_tabval)
-            {
-              tabval = 0;
-              have_tabval = true;
-              num_start = stops;
-            }
-
-          /* Detect overflow.  */
-          if (!DECIMAL_DIGIT_ACCUMULATE (tabval, *stops - '0', uintmax_t))
-            {
-              size_t len = strspn (num_start, "0123456789");
-              char *bad_num = xstrndup (num_start, len);
-              error (0, 0, _("tab stop is too large %s"), quote (bad_num));
-              free (bad_num);
-              ok = false;
-              stops = num_start + len - 1;
-            }
-        }
-      else
-        {
-          error (0, 0, _("tab size contains invalid character(s): %s"),
-                 quote (stops));
-          ok = false;
-          break;
-        }
-    }
-
-  if (!ok)
-    exit (EXIT_FAILURE);
-
-  if (have_tabval)
-    add_tab_stop (tabval);
-}
-
-/* Check that the list of tab stops TABS, with ENTRIES entries,
-   contains only nonzero, ascending values.  */
-
-static void
-validate_tab_stops (uintmax_t const *tabs, size_t entries)
-{
-  uintmax_t prev_tab = 0;
-  size_t i;
-
-  for (i = 0; i < entries; i++)
-    {
-      if (tabs[i] == 0)
-        error (EXIT_FAILURE, 0, _("tab size cannot be 0"));
-      if (tabs[i] <= prev_tab)
-        error (EXIT_FAILURE, 0, _("tab sizes must be ascending"));
-      prev_tab = tabs[i];
-    }
-}
-
-/* Close the old stream pointer FP if it is non-NULL,
-   and return a new one opened to read the next input file.
-   Open a filename of '-' as the standard input.
-   Return NULL if there are no more input files.  */
-
-static FILE *
-next_file (FILE *fp)
-{
-  static char *prev_file;
-  char *file;
-
-  if (fp)
-    {
-      if (ferror (fp))
-        {
-          error (0, errno, "%s", quotef (prev_file));
-          exit_status = EXIT_FAILURE;
-        }
-      if (STREQ (prev_file, "-"))
-        clearerr (fp);		/* Also clear EOF.  */
-      else if (fclose (fp) != 0)
-        {
-          error (0, errno, "%s", quotef (prev_file));
-          exit_status = EXIT_FAILURE;
-        }
-    }
-
-  while ((file = *file_list++) != NULL)
-    {
-      if (STREQ (file, "-"))
-        {
-          have_read_stdin = true;
-          fp = stdin;
-        }
-      else
-        fp = fopen (file, "r");
-      if (fp)
-        {
-          prev_file = file;
-          fadvise (fp, FADVISE_SEQUENTIAL);
-          return fp;
-        }
-      error (0, errno, "%s", quotef (file));
-      exit_status = EXIT_FAILURE;
-    }
-  return NULL;
-}
-
 /* Change tabs to spaces, writing to stdout.
    Read each file in 'file_list', in order.  */
 
@@ -265,19 +147,19 @@ expand (void)
 {
   /* Input stream.  */
   FILE *fp = next_file (NULL);
+  mb_file_t mbf;
+  mbf_char_t c;
 
   if (!fp)
     return;
 
+  mbf_init (mbf, fp);
+
   while (true)
     {
-      /* Input character, or EOF.  */
-      int c;
-
       /* If true, perform translations.  */
       bool convert = true;
 
-
       /* The following variables have valid values only when CONVERT
          is true:  */
 
@@ -287,17 +169,23 @@ expand (void)
       /* Index in TAB_LIST of next tab stop to examine.  */
       size_t tab_index = 0;
 
-
       /* Convert a line of text.  */
 
       do
         {
-          while ((c = getc (fp)) < 0 && (fp = next_file (fp)))
-            continue;
+          do {
+            mbf_getc (c, mbf);
+            if (mb_iseof (c))
+              {
+                mbf_init (mbf, fp = next_file (fp));
+                continue;
+              }
+            }
+          while (false);
 
           if (convert)
             {
-              if (c == '\t')
+              if (mb_iseq (c, '\t'))
                 {
                   /* Column the next input tab stop is on.  */
                   uintmax_t next_tab_column;
@@ -328,32 +216,34 @@ expand (void)
                     if (putchar (' ') < 0)
                       error (EXIT_FAILURE, errno, _("write error"));
 
-                  c = ' ';
+                  mb_setascii (&c, ' ');
                 }
-              else if (c == '\b')
+              else if (mb_iseq (c, '\b'))
                 {
                   /* Go back one column, and force recalculation of the
                      next tab stop.  */
                   column -= !!column;
                   tab_index -= !!tab_index;
                 }
-              else
+              /* A leading control character could make us trip over.  */
+              else if (!mb_iscntrl (c))
                 {
-                  column++;
+                  column += mb_width (c);
                   if (!column)
                     error (EXIT_FAILURE, 0, _("input line is too long"));
                 }
 
-              convert &= convert_entire_line || !! isblank (c);
+              convert &= convert_entire_line || mb_isblank (c);
             }
 
-          if (c < 0)
+          if (mb_iseof (c))
             return;
 
-          if (putchar (c) < 0)
+          mb_putc (c, stdout);
+          if (ferror (stdout))
             error (EXIT_FAILURE, errno, _("write error"));
         }
-      while (c != '\n');
+      while (!mb_iseq (c, '\n'));
     }
 }
 
@@ -385,19 +275,19 @@ main (int argc, char **argv)
           break;
 
         case 't':
-          parse_tab_stops (optarg);
+          parse_tab_stops (optarg, add_tab_stop);
           break;
 
         case '0': case '1': case '2': case '3': case '4':
         case '5': case '6': case '7': case '8': case '9':
           if (optarg)
-            parse_tab_stops (optarg - 1);
+            parse_tab_stops (optarg - 1, add_tab_stop);
           else
             {
               char tab_stop[2];
               tab_stop[0] = c;
               tab_stop[1] = '\0';
-              parse_tab_stops (tab_stop);
+              parse_tab_stops (tab_stop, add_tab_stop);
             }
           break;
 
diff --git a/src/local.mk b/src/local.mk
index 536b7cc..bfede88 100644
--- a/src/local.mk
+++ b/src/local.mk
@@ -361,6 +361,8 @@ src_coreutils_SOURCES = src/coreutils.c
 
 src_cp_SOURCES = src/cp.c $(copy_sources) $(selinux_sources)
 src_dir_SOURCES = src/ls.c src/ls-dir.c
+src_expand_SOURCES = src/expand.c src/expand-core.c
+src_unexpand_SOURCES = src/unexpand.c src/expand-core.c
 src_vdir_SOURCES = src/ls.c src/ls-vdir.c
 src_id_SOURCES = src/id.c src/group-list.c
 src_groups_SOURCES = src/groups.c src/group-list.c
diff --git a/src/unexpand.c b/src/unexpand.c
index e0f7c22..48fbb32 100644
--- a/src/unexpand.c
+++ b/src/unexpand.c
@@ -38,12 +38,16 @@
 #include <stdio.h>
 #include <getopt.h>
 #include <sys/types.h>
+
+#include <mbfile.h>
+
 #include "system.h"
 #include "error.h"
 #include "fadvise.h"
-#include "quote.h"
 #include "xstrndup.h"
 
+#include "expand-core.h"
+
 /* The official name of this program (e.g., no 'g' prefix).  */
 #define PROGRAM_NAME "unexpand"
 
@@ -62,17 +66,17 @@ static size_t max_column_width;
 /* Array of the explicit column numbers of the tab stops;
    after 'tab_list' is exhausted, the rest of the line is printed
    unchanged.  The first column is column 0.  */
-static uintmax_t *tab_list;
+uintmax_t *tab_list;
 
 /* The number of allocated entries in 'tab_list'.  */
-static size_t n_tabs_allocated;
+size_t n_tabs_allocated;
 
 /* The index of the first invalid element of 'tab_list',
    where the next element can be added.  */
-static size_t first_free_tab;
+size_t first_free_tab;
 
 /* Null-terminated array of input filenames.  */
-static char **file_list;
+char **file_list;
 
 /* Default for 'file_list' if no files are given on the command line.  */
 static char *stdin_argv[] =
@@ -81,10 +85,10 @@ static char *stdin_argv[] =
 };
 
 /* True if we have ever read standard input.  */
-static bool have_read_stdin;
+bool have_read_stdin;
 
 /* The desired exit status.  */
-static int exit_status;
+int exit_status;
 
 /* For long options that have no equivalent short option, use a
    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
@@ -154,128 +158,6 @@ add_tab_stop (uintmax_t tabval)
     }
 }
 
-/* Add the comma or blank separated list of tab stops STOPS
-   to the list of tab stops.  */
-
-static void
-parse_tab_stops (char const *stops)
-{
-  bool have_tabval = false;
-  uintmax_t tabval IF_LINT ( = 0);
-  char const *num_start IF_LINT ( = NULL);
-  bool ok = true;
-
-  for (; *stops; stops++)
-    {
-      if (*stops == ',' || isblank (to_uchar (*stops)))
-        {
-          if (have_tabval)
-            add_tab_stop (tabval);
-          have_tabval = false;
-        }
-      else if (ISDIGIT (*stops))
-        {
-          if (!have_tabval)
-            {
-              tabval = 0;
-              have_tabval = true;
-              num_start = stops;
-            }
-
-          /* Detect overflow.  */
-          if (!DECIMAL_DIGIT_ACCUMULATE (tabval, *stops - '0', uintmax_t))
-            {
-              size_t len = strspn (num_start, "0123456789");
-              char *bad_num = xstrndup (num_start, len);
-              error (0, 0, _("tab stop is too large %s"), quote (bad_num));
-              free (bad_num);
-              ok = false;
-              stops = num_start + len - 1;
-            }
-        }
-      else
-        {
-          error (0, 0, _("tab size contains invalid character(s): %s"),
-                 quote (stops));
-          ok = false;
-          break;
-        }
-    }
-
-  if (!ok)
-    exit (EXIT_FAILURE);
-
-  if (have_tabval)
-    add_tab_stop (tabval);
-}
-
-/* Check that the list of tab stops TABS, with ENTRIES entries,
-   contains only nonzero, ascending values.  */
-
-static void
-validate_tab_stops (uintmax_t const *tabs, size_t entries)
-{
-  uintmax_t prev_tab = 0;
-  size_t i;
-
-  for (i = 0; i < entries; i++)
-    {
-      if (tabs[i] == 0)
-        error (EXIT_FAILURE, 0, _("tab size cannot be 0"));
-      if (tabs[i] <= prev_tab)
-        error (EXIT_FAILURE, 0, _("tab sizes must be ascending"));
-      prev_tab = tabs[i];
-    }
-}
-
-/* Close the old stream pointer FP if it is non-NULL,
-   and return a new one opened to read the next input file.
-   Open a filename of '-' as the standard input.
-   Return NULL if there are no more input files.  */
-
-static FILE *
-next_file (FILE *fp)
-{
-  static char *prev_file;
-  char *file;
-
-  if (fp)
-    {
-      if (ferror (fp))
-        {
-          error (0, errno, "%s", quotef (prev_file));
-          exit_status = EXIT_FAILURE;
-        }
-      if (STREQ (prev_file, "-"))
-        clearerr (fp);		/* Also clear EOF.  */
-      else if (fclose (fp) != 0)
-        {
-          error (0, errno, "%s", quotef (prev_file));
-          exit_status = EXIT_FAILURE;
-        }
-    }
-
-  while ((file = *file_list++) != NULL)
-    {
-      if (STREQ (file, "-"))
-        {
-          have_read_stdin = true;
-          fp = stdin;
-        }
-      else
-        fp = fopen (file, "r");
-      if (fp)
-        {
-          prev_file = file;
-          fadvise (fp, FADVISE_SEQUENTIAL);
-          return fp;
-        }
-      error (0, errno, "%s", quotef (file));
-      exit_status = EXIT_FAILURE;
-    }
-  return NULL;
-}
-
 /* Change blanks to tabs, writing to stdout.
    Read each file in 'file_list', in order.  */
 
@@ -284,11 +166,12 @@ unexpand (void)
 {
   /* Input stream.  */
   FILE *fp = next_file (NULL);
+  mb_file_t mbf;
 
   /* The array of pending blanks.  In non-POSIX locales, blanks can
      include characters other than spaces, so the blanks must be
      stored, not merely counted.  */
-  char *pending_blank;
+  mbf_char_t *pending_blank;
 
   if (!fp)
     return;
@@ -296,12 +179,14 @@ unexpand (void)
   /* The worst case is a non-blank character, then one blank, then a
      tab stop, then MAX_COLUMN_WIDTH - 1 blanks, then a non-blank; so
      allocate MAX_COLUMN_WIDTH bytes to store the blanks.  */
-  pending_blank = xmalloc (max_column_width);
+  pending_blank = xmalloc (max_column_width * sizeof (mbf_char_t));
+
+  mbf_init (mbf, fp);
 
   while (true)
     {
       /* Input character, or EOF.  */
-      int c;
+      mbf_char_t c;
 
       /* If true, perform translations.  */
       bool convert = true;
@@ -335,12 +220,19 @@ unexpand (void)
 
       do
         {
-          while ((c = getc (fp)) < 0 && (fp = next_file (fp)))
-            continue;
+          do {
+            mbf_getc (c, mbf);
+            if (mb_iseof (c))
+              {
+                mbf_init (mbf, fp = next_file (fp));
+                continue;
+              }
+            }
+          while (false);
 
           if (convert)
             {
-              bool blank = !! isblank (c);
+              bool blank = mb_isblank (c);
 
               if (blank)
                 {
@@ -372,16 +264,16 @@ unexpand (void)
                       if (next_tab_column < column)
                         error (EXIT_FAILURE, 0, _("input line is too long"));
 
-                      if (c == '\t')
+                      if (mb_iseq (c, '\t'))
                         {
                           column = next_tab_column;
 
                           if (pending)
-                            pending_blank[0] = '\t';
+                            mb_setascii (&pending_blank[0], '\t');
                         }
                       else
                         {
-                          column++;
+                          column += mb_width (c);
 
                           if (! (prev_blank && column == next_tab_column))
                             {
@@ -389,13 +281,14 @@ unexpand (void)
                                  will be replaced by tabs.  */
                               if (column == next_tab_column)
                                 one_blank_before_tab_stop = true;
-                              pending_blank[pending++] = c;
+                              mb_copy (&pending_blank[pending++], &c);
                               prev_blank = true;
                               continue;
                             }
 
                           /* Replace the pending blanks by a tab or two.  */
-                          pending_blank[0] = c = '\t';
+                          mb_setascii (&c, '\t');
+                          mb_setascii (&pending_blank[0], '\t');
                         }
 
                       /* Discard pending blanks, unless it was a single
@@ -403,7 +296,7 @@ unexpand (void)
                       pending = one_blank_before_tab_stop;
                     }
                 }
-              else if (c == '\b')
+              else if (mb_iseq (c, '\b'))
                 {
                   /* Go back one column, and force recalculation of the
                      next tab stop.  */
@@ -413,7 +306,7 @@ unexpand (void)
                 }
               else
                 {
-                  column++;
+                  column += mb_width (c);
                   if (!column)
                     error (EXIT_FAILURE, 0, _("input line is too long"));
                 }
@@ -421,9 +314,13 @@ unexpand (void)
               if (pending)
                 {
                   if (pending > 1 && one_blank_before_tab_stop)
-                    pending_blank[0] = '\t';
-                  if (fwrite (pending_blank, 1, pending, stdout) != pending)
+                    mb_setascii (&pending_blank[0], '\t');
+
+                  for (int n = 0; n < pending; ++n)
+                    mb_putc (pending_blank[n], stdout);
+                  if (ferror (stdout))
                     error (EXIT_FAILURE, errno, _("write error"));
+
                   pending = 0;
                   one_blank_before_tab_stop = false;
                 }
@@ -432,16 +329,16 @@ unexpand (void)
               convert &= convert_entire_line || blank;
             }
 
-          if (c < 0)
+          if (mb_iseof (c))
             {
               free (pending_blank);
               return;
             }
-
-          if (putchar (c) < 0)
+          mb_putc (c, stdout);
+          if (ferror (stdout))
             error (EXIT_FAILURE, errno, _("write error"));
         }
-      while (c != '\n');
+      while (!mb_iseq (c, '\n'));
     }
 }
 
@@ -482,7 +379,7 @@ main (int argc, char **argv)
           break;
         case 't':
           convert_entire_line = true;
-          parse_tab_stops (optarg);
+          parse_tab_stops (optarg, add_tab_stop);
           break;
         case CONVERT_FIRST_ONLY_OPTION:
           convert_first_only = true;
diff --git a/tests/expand/mb.sh b/tests/expand/mb.sh
new file mode 100755
index 0000000..7971e18
--- /dev/null
+++ b/tests/expand/mb.sh
@@ -0,0 +1,98 @@
+#!/bin/sh
+
+# Copyright (C) 2012-2015 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 3 of the License, 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, see <http://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
+print_ver_ expand
+
+export LC_ALL=en_US.UTF-8
+
+#input containing multibyte characters
+cat <<\EOF > in || framework_failure_
+1234567812345678123456781
+.       .       .       .
+a	b	c	d
+.       .       .       .
+ä	ö	ü	ß
+.       .       .       .
+EOF
+env printf '   äöü\t.    öüä.   \tä xx\n' >> in || framework_failure_
+
+cat <<\EOF > exp || framework_failure_
+1234567812345678123456781
+.       .       .       .
+a       b       c       d
+.       .       .       .
+ä       ö       ü       ß
+.       .       .       .
+   äöü  .    öüä.       ä xx
+EOF
+
+expand < in > out || fail=1
+compare exp out > /dev/null 2>&1 || fail=1
+
+#test characters with display widths != 1
+env printf '12345678
+e\t|ascii(1)
+\u00E9\t|composed(1)
+e\u0301\t|decomposed(1)
+\u3000\t|ideo-space(2)
+\uFF0D\t|full-hypen(2)
+' > in || framework_failure_
+
+env printf '12345678
+e       |ascii(1)
+\u00E9       |composed(1)
+e\u0301       |decomposed(1)
+\u3000      |ideo-space(2)
+\uFF0D      |full-hypen(2)
+' > exp || framework_failure_
+
+expand < in > out || fail=1
+compare exp out > /dev/null 2>&1 || fail=1
+
+#shouldn't fail with "input line too long"
+#when a line starts with a control character
+env printf '\n' > in || framework_failure_
+
+expand < in > out || fail=1
+compare in out > /dev/null 2>&1 || fail=1
+
+#non-Unicode characters interspersed between Unicode ones
+env printf '12345678
+\t\xFF|
+\xFF\t|
+\t\xFFä|
+ä\xFF\t|
+\tä\xFF|
+\xFF\tä|
+äbcdef\xFF\t|
+' > in || framework_failure_
+
+env printf '12345678
+        \xFF|
+\xFF       |
+        \xFFä|
+ä\xFF      |
+        ä\xFF|
+\xFF       ä|
+äbcdef\xFF |
+' > exp || framework_failure_
+
+expand < in > out || fail=1
+compare exp out > /dev/null 2>&1 || fail=1
+
+exit $fail
diff --git a/tests/local.mk b/tests/local.mk
index 7df04da..d3462be 100644
--- a/tests/local.mk
+++ b/tests/local.mk
@@ -536,6 +536,7 @@ all_tests =					\
   tests/du/threshold.sh				\
   tests/du/trailing-slash.sh			\
   tests/du/two-args.sh				\
+  tests/expand/mb.sh				\
   tests/id/gnu-zero-uids.sh			\
   tests/id/no-context.sh			\
   tests/id/context.sh				\
@@ -674,6 +675,7 @@ all_tests =					\
   tests/touch/read-only.sh			\
   tests/touch/relative.sh			\
   tests/touch/trailing-slash.sh			\
+  tests/unexpand/mb.sh				\
   $(all_root_tests)
 
 # See tests/factor/create-test.sh.
diff --git a/tests/unexpand/mb.sh b/tests/unexpand/mb.sh
new file mode 100755
index 0000000..60d4c1a
--- /dev/null
+++ b/tests/unexpand/mb.sh
@@ -0,0 +1,97 @@
+#!/bin/sh
+
+# Copyright (C) 2012-2015 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 3 of the License, 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, see <http://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
+print_ver_ unexpand
+
+export LC_ALL=en_US.UTF-8
+
+#input containing multibyte characters
+cat > in <<\EOF
+1234567812345678123456781
+.       .       .       .
+a       b       c       d
+.       .       .       .
+ä       ö       ü       ß
+.       .       .       .
+   äöü  .    öüä.       ä xx
+EOF
+
+cat > exp <<\EOF
+1234567812345678123456781
+.	.	.	.
+a	b	c	d
+.	.	.	.
+ä	ö	ü	ß
+.	.	.	.
+   äöü	.    öüä.	ä xx
+EOF
+
+unexpand -a < in > out || fail=1
+compare exp out > /dev/null 2>&1 || fail=1
+
+#test characters with a display width larger than 1
+
+env printf '12345678
+e       |ascii(1)
+\u00E9       |composed(1)
+e\u0301       |decomposed(1)
+\u3000      |ideo-space(2)
+\uFF0D      |full-hypen(2)
+' > in || framework_failure_
+
+env printf '12345678
+e\t|ascii(1)
+\u00E9\t|composed(1)
+e\u0301\t|decomposed(1)
+\u3000\t|ideo-space(2)
+\uFF0D\t|full-hypen(2)
+' > exp || framework_failure_
+
+unexpand -a < in > out || fail=1
+compare exp out > /dev/null 2>&1 || fail=1
+
+#test input where a blank of width > 1 is not being substituted
+in="$(LC_ALL=en_US.UTF-8 printf ' \u3000  ö       ü       ß')"
+exp=' 　  ö	     ü	     ß'
+
+unexpand -a < in > out || fail=1
+compare exp out > /dev/null 2>&1 || fail=1
+
+#non-Unicode characters interspersed between Unicode ones
+env printf '12345678
+        \xFF|
+\xFF       |
+        \xFFä|
+ä\xFF      |
+        ä\xFF|
+\xFF       ä|
+äbcdef\xFF |
+' > in || framework_failure_
+
+env printf '12345678
+\t\xFF|
+\xFF\t|
+\t\xFFä|
+ä\xFF\t|
+\tä\xFF|
+\xFF\tä|
+äbcdef\xFF\t|
+' > exp || framework_failure_
+
+unexpand -a < in > out || fail=1
+compare exp out > /dev/null 2>&1 || fail=1
diff --git a/m4/mbfile.m4 b/m4/mbfile.m4
new file mode 100644
index 0000000..8589902
--- /dev/null
+++ b/m4/mbfile.m4
@@ -0,0 +1,14 @@
+# mbfile.m4 serial 7
+dnl Copyright (C) 2005, 2008-2015 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.
+
+dnl autoconf tests required for use of mbfile.h
+dnl From Bruno Haible.
+
+AC_DEFUN([gl_MBFILE],
+[
+  AC_REQUIRE([AC_TYPE_MBSTATE_T])
+  :
+])
diff --git a/lib/mbfile.c b/lib/mbfile.c
new file mode 100644
index 0000000..b0a468e
--- /dev/null
+++ b/lib/mbfile.c
@@ -0,0 +1,3 @@
+#include <config.h>
+#define MBFILE_INLINE _GL_EXTERN_INLINE
+#include "mbfile.h"
diff --git a/lib/mbfile.h b/lib/mbfile.h
new file mode 100644
index 0000000..11f1b12
--- /dev/null
+++ b/lib/mbfile.h
@@ -0,0 +1,255 @@
+/* Multibyte character I/O: macros for multi-byte encodings.
+   Copyright (C) 2001, 2005, 2009-2015 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 3 of the License, 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, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Mitsuru Chinen <mchinen@yamato.ibm.com>
+   and Bruno Haible <bruno@clisp.org>.  */
+
+/* The macros in this file implement multi-byte character input from a
+   stream.
+
+   mb_file_t
+     is the type for multibyte character input stream, usable for variable
+     declarations.
+
+   mbf_char_t
+     is the type for multibyte character or EOF, usable for variable
+     declarations.
+
+   mbf_init (mbf, stream)
+     initializes the MB_FILE for reading from stream.
+
+   mbf_getc (mbc, mbf)
+     reads the next multibyte character from mbf and stores it in mbc.
+
+   mb_iseof (mbc)
+     returns true if mbc represents the EOF value.
+
+   Here are the function prototypes of the macros.
+
+   extern void          mbf_init (mb_file_t mbf, FILE *stream);
+   extern void          mbf_getc (mbf_char_t mbc, mb_file_t mbf);
+   extern bool          mb_iseof (const mbf_char_t mbc);
+ */
+
+#ifndef _MBFILE_H
+#define _MBFILE_H 1
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.1 has a bug: <stdio.h> and <time.h> must be included before
+   <wchar.h>.  */
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>
+
+#include "mbchar.h"
+
+#ifndef _GL_INLINE_HEADER_BEGIN
+ #error "Please include config.h first."
+#endif
+_GL_INLINE_HEADER_BEGIN
+#ifndef MBFILE_INLINE
+# define MBFILE_INLINE _GL_INLINE
+#endif
+
+struct mbfile_multi {
+  FILE *fp;
+  bool eof_seen;
+  bool have_pushback;
+  mbstate_t state;
+  unsigned int bufcount;
+  char buf[MBCHAR_BUF_SIZE];
+  struct mbchar pushback;
+};
+
+MBFILE_INLINE void
+mbfile_multi_getc (struct mbchar *mbc, struct mbfile_multi *mbf)
+{
+  size_t bytes;
+
+  /* If EOF has already been seen, don't use getc.  This matters if
+     mbf->fp is connected to an interactive tty.  */
+  if (mbf->eof_seen)
+    goto eof;
+
+  /* Return character pushed back, if there is one.  */
+  if (mbf->have_pushback)
+    {
+      mb_copy (mbc, &mbf->pushback);
+      mbf->have_pushback = false;
+      return;
+    }
+
+  /* Before using mbrtowc, we need at least one byte.  */
+  if (mbf->bufcount == 0)
+    {
+      int c = getc (mbf->fp);
+      if (c == EOF)
+        {
+          mbf->eof_seen = true;
+          goto eof;
+        }
+      mbf->buf[0] = (unsigned char) c;
+      mbf->bufcount++;
+    }
+
+  /* Handle most ASCII characters quickly, without calling mbrtowc().  */
+  if (mbf->bufcount == 1 && mbsinit (&mbf->state) && is_basic (mbf->buf[0]))
+    {
+      /* These characters are part of the basic character set.  ISO C 99
+         guarantees that their wide character code is identical to their
+         char code.  */
+      mbc->wc = mbc->buf[0] = mbf->buf[0];
+      mbc->wc_valid = true;
+      mbc->ptr = &mbc->buf[0];
+      mbc->bytes = 1;
+      mbf->bufcount = 0;
+      return;
+    }
+
+  /* Use mbrtowc on an increasing number of bytes.  Read only as many bytes
+     from mbf->fp as needed.  This is needed to give reasonable interactive
+     behaviour when mbf->fp is connected to an interactive tty.  */
+  for (;;)
+    {
+      /* We don't know whether the 'mbrtowc' function updates the state when
+         it returns -2, - this is the ISO C 99 and glibc-2.2 behaviour - or
+         not - amended ANSI C, glibc-2.1 and Solaris 2.7 behaviour.  We
+         don't have an autoconf test for this, yet.
+         The new behaviour would allow us to feed the bytes one by one into
+         mbrtowc.  But the old behaviour forces us to feed all bytes since
+         the end of the last character into mbrtowc.  Since we want to retry
+         with more bytes when mbrtowc returns -2, we must backup the state
+         before calling mbrtowc, because implementations with the new
+         behaviour will clobber it.  */
+      mbstate_t backup_state = mbf->state;
+
+      bytes = mbrtowc (&mbc->wc, &mbf->buf[0], mbf->bufcount, &mbf->state);
+
+      if (bytes == (size_t) -1)
+        {
+          /* An invalid multibyte sequence was encountered.  */
+          /* Return a single byte.  */
+          bytes = 1;
+          mbc->wc_valid = false;
+          break;
+        }
+      else if (bytes == (size_t) -2)
+        {
+          /* An incomplete multibyte character.  */
+          mbf->state = backup_state;
+          if (mbf->bufcount == MBCHAR_BUF_SIZE)
+            {
+              /* An overlong incomplete multibyte sequence was encountered.  */
+              /* Return a single byte.  */
+              bytes = 1;
+              mbc->wc_valid = false;
+              break;
+            }
+          else
+            {
+              /* Read one more byte and retry mbrtowc.  */
+              int c = getc (mbf->fp);
+              if (c == EOF)
+                {
+                  /* An incomplete multibyte character at the end.  */
+                  mbf->eof_seen = true;
+                  bytes = mbf->bufcount;
+                  mbc->wc_valid = false;
+                  break;
+                }
+              mbf->buf[mbf->bufcount] = (unsigned char) c;
+              mbf->bufcount++;
+            }
+        }
+      else
+        {
+          if (bytes == 0)
+            {
+              /* A null wide character was encountered.  */
+              bytes = 1;
+              assert (mbf->buf[0] == '\0');
+              assert (mbc->wc == 0);
+            }
+          mbc->wc_valid = true;
+          break;
+        }
+    }
+
+  /* Return the multibyte sequence mbf->buf[0..bytes-1].  */
+  mbc->ptr = &mbc->buf[0];
+  memcpy (&mbc->buf[0], &mbf->buf[0], bytes);
+  mbc->bytes = bytes;
+
+  mbf->bufcount -= bytes;
+  if (mbf->bufcount > 0)
+    {
+      /* It's not worth calling memmove() for so few bytes.  */
+      unsigned int count = mbf->bufcount;
+      char *p = &mbf->buf[0];
+
+      do
+        {
+          *p = *(p + bytes);
+          p++;
+        }
+      while (--count > 0);
+    }
+  return;
+
+eof:
+  /* An mbchar_t with bytes == 0 is used to indicate EOF.  */
+  mbc->ptr = NULL;
+  mbc->bytes = 0;
+  mbc->wc_valid = false;
+  return;
+}
+
+MBFILE_INLINE void
+mbfile_multi_ungetc (const struct mbchar *mbc, struct mbfile_multi *mbf)
+{
+  mb_copy (&mbf->pushback, mbc);
+  mbf->have_pushback = true;
+}
+
+typedef struct mbfile_multi mb_file_t;
+
+typedef mbchar_t mbf_char_t;
+
+#define mbf_init(mbf, stream)                                           \
+  ((mbf).fp = (stream),                                                 \
+   (mbf).eof_seen = false,                                              \
+   (mbf).have_pushback = false,                                         \
+   memset (&(mbf).state, '\0', sizeof (mbstate_t)),                     \
+   (mbf).bufcount = 0)
+
+#define mbf_getc(mbc, mbf) mbfile_multi_getc (&(mbc), &(mbf))
+
+#define mbf_ungetc(mbc, mbf) mbfile_multi_ungetc (&(mbc), &(mbf))
+
+#define mb_iseof(mbc) ((mbc).bytes == 0)
+
+#ifndef _GL_INLINE_HEADER_BEGIN
+ #error "Please include config.h first."
+#endif
+_GL_INLINE_HEADER_BEGIN
+
+#endif /* _MBFILE_H */
-- 
2.5.5