maint: update copyright dates

build: update gnulib to latest, and update bootstrap
diff: tweak -q, -s doc
2026-01-29 19:04:12 +00:00 · 2026-01-02 16:52:26 -08:00 · 2026-01-02 16:51:54 -08:00 · 2025-12-07 09:41:44 -08:00 · 2025-12-03 09:40:35 -08:00 · 2025-12-03 09:40:35 -08:00
54 changed files with 713 additions and 1233 deletions
--- a/.prev-version
+++ b/.prev-version
@ -1 +1 @@
-3.10
+3.12
--- a/2
+++ b/2
@ -33,7 +33,7 @@ Patrick D'Cruze
 Eli Zaretskii


-Copyright (C) 2001, 2006, 2009-2013, 2015-2025 Free Software Foundation, Inc.
+Copyright (C) 2001, 2006, 2009-2013, 2015-2026 Free Software Foundation, Inc.

 This file is part of GNU diffutils.

--- a/2
+++ b/2
@ -4265,7 +4265,7 @@ Thu Nov  3 16:30:24 1988  Randall Smith  (randy at gluteus.ai.mit.edu)

 	-----

-	Copyright (C) 1988-1994, 1997-2002, 2004, 2006, 2009-2013, 2015-2025
+	Copyright (C) 1988-1994, 1997-2002, 2004, 2006, 2009-2013, 2015-2026
 	Free Software Foundation, Inc.

 	Copying and distribution of this file, with or without
--- a/2
+++ b/2
@ -568,7 +568,7 @@ Then just open the index.html file (in the generated lcov-html directory)
 in your favorite web browser.

 ========================================================================
-Copyright (C) 2009-2013, 2015-2025 Free Software Foundation, Inc.
+Copyright (C) 2009-2013, 2015-2026 Free Software Foundation, Inc.

 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3 or
--- a/Makefile.am
+++ b/Makefile.am
@ -1,6 +1,6 @@
 # Main Automakefile for GNU diffutils.

-# Copyright (C) 2001-2002, 2004, 2006, 2009-2013, 2015-2025 Free Software
+# Copyright (C) 2001-2002, 2004, 2006, 2009-2013, 2015-2026 Free Software
 # Foundation, Inc.

 # This program is free software: you can redistribute it and/or modify
--- a/17
+++ b/17
@ -1,5 +1,20 @@
 GNU diffutils NEWS                                    -*- outline -*-

+* Noteworthy changes in release ?.? (????-??-??) [?]
+
+
+* Noteworthy changes in release 3.12 (2025-04-08) [stable]
+
+** Bug fixes
+
+  diff -r no longer merely summarizes when comparing an empty regular
+  file to a nonempty regular file.
+  [bug#76452 introduced in 3.11]
+
+  diff -y no longer crashes when given nontrivial differences.
+  [bug#76613 introduced in 3.11]
+
+
 * Noteworthy changes in release 3.11 (2025-02-02) [stable]

 ** Improvements
@ -533,7 +548,7 @@ User-visible changes in version 2.0:



-Copyright (C) 1993-1994, 1998, 2001-2002, 2004, 2006, 2009-2013, 2015-2025 Free
+Copyright (C) 1993-1994, 1998, 2001-2002, 2004, 2006, 2009-2013, 2015-2026 Free
 Software Foundation, Inc.

 This file is part of GNU Diffutils.
--- a/15
+++ b/15
@ -30,19 +30,12 @@ installation.  If you have an older version of libiconv, please
 upgrade to the latest one; see <ftp://ftp.gnu.org/gnu/libiconv/>.  If
 the problem seems isolated to diffutils, though, please report a bug.

-This program requires a Standard C compiler (C89 or later).  If you
+This program requires a Standard C compiler (C99 or later).  If you
 have a nonstandard compiler, please install GCC first.

 If you make changes to the source code, you may need appropriate
-versions of GNU build tools to regenerate the intermediate files.  The
-following versions were used to generate the intermediate files in
-this distribution:
-
-* Autoconf 2.59   <ftp://ftp.gnu.org/gnu/autoconf/autoconf-2.59.tar.gz>
-* Automake 1.8.3  <ftp://ftp.gnu.org/gnu/automake/automake-1.8.3.tar.gz>
-* gettext 0.14.1  <ftp://ftp.gnu.org/gnu/gettext/gettext-0.14.1.tar.gz>
-* help2man 1.33   <ftp://ftp.gnu.org/gnu/help2man/help2man-1.33.1.tar.gz>
-* Texinfo 4.7     <ftp://ftp.gnu.org/gnu/texinfo/texinfo-4.7.tar.gz>
+versions of GNU build tools to regenerate the intermediate files.
+See README-prereq for details.

 For any copyright year range specified as YYYY-ZZZZ in this package
 note that the range specifies every single year in that closed interval.
@ -51,7 +44,7 @@ Please report bugs to <bug-diffutils@gnu.org>.

 -----

-Copyright (C) 1992, 1998, 2001-2002, 2004, 2009-2013, 2015-2025 Free Software
+Copyright (C) 1992, 1998, 2001-2002, 2004, 2009-2013, 2015-2026 Free Software
 Foundation, Inc.

 This file is part of GNU Diffutils.
--- a/2
+++ b/2
@ -119,7 +119,7 @@ diffutils:

 -----

-Copyright (C) 2002-2025 Free Software Foundation, Inc.
+Copyright (C) 2002-2026 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
--- a/8
+++ b/8
@ -24,14 +24,14 @@ too-old versions first as they may be needed to build newer versions.

 Here is an example of how to build a program from source.  This
 example is for Autoconf; a similar approach should work for the other
-developer prerequisites.  This example assumes Autoconf 2.71; it
+developer prerequisites.  This example assumes Autoconf 2.72; it
 should be OK to use a later version of Autoconf, if available.

  prefix=$HOME/prefix   # (or wherever else you choose)
  export PATH=$prefix/bin:$PATH
-  wget https://ftp.gnu.org/pub/gnu/autoconf/autoconf-2.71.tar.gz
-  gzip -d <autoconf-2.71.tar.gz | tar xf -
-  cd autoconf-2.71
+  wget https://ftp.gnu.org/pub/gnu/autoconf/autoconf-2.72.tar.gz
+  gzip -d <autoconf-2.72.tar.gz | tar xf -
+  cd autoconf-2.72
  ./configure --prefix=$prefix
  make install

--- a/32
+++ b/32
@ -3,9 +3,9 @@

 # Bootstrap this package from checked-out sources.

-scriptversion=2024-07-04.10; # UTC
+scriptversion=2025-06-10.02; # UTC

-# Copyright (C) 2003-2025 Free Software Foundation, Inc.
+# Copyright (C) 2003-2026 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
@ -37,9 +37,9 @@ medir=`dirname "$me"`

 # A library of shell functions for autopull.sh, autogen.sh, and bootstrap.

-scriptlibversion=2025-01-26.03; # UTC
+scriptlibversion=2025-12-04.19; # UTC

-# Copyright (C) 2003-2025 Free Software Foundation, Inc.
+# Copyright (C) 2003-2026 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
@ -72,7 +72,7 @@ export LC_ALL
 # Honor $PERL, but work even if there is none.
 PERL="${PERL-perl}"

-default_gnulib_url=https://git.savannah.gnu.org/git/gnulib.git
+default_gnulib_url=https://https.git.savannah.gnu.org/git/gnulib.git

 # Copyright year, for the --version output.
 copyright_year=`echo "$scriptlibversion" | sed -e 's/[^0-9].*//'`
@ -580,17 +580,11 @@ prepare_GNULIB_SRCDIR ()
          || cleanup_gnulib
        else
          # GNULIB_REFDIR is not set or not usable. Ignore it.
-          shallow=
+          shallow='--depth 2'
          if test -z "$GNULIB_REVISION"; then
-            if git clone -h 2>&1 | grep -- --depth > /dev/null; then
-              shallow='--depth 2'
-            fi
            git clone $shallow "$gnulib_url" "$gnulib_path" \
              || cleanup_gnulib
          else
-            if git fetch -h 2>&1 | grep -- --depth > /dev/null; then
-              shallow='--depth 2'
-            fi
            # Only want a shallow checkout of $GNULIB_REVISION, but git does not
            # support cloning by commit hash. So attempt a shallow fetch by
            # commit hash to minimize the amount of data downloaded and changes
@ -601,7 +595,10 @@ prepare_GNULIB_SRCDIR ()
            # to fetching all commits.
            # $GNULIB_REVISION can be a commit id, a tag name, or a branch name.
            mkdir -p "$gnulib_path"
-            git -C "$gnulib_path" init
+            # Use a -c option to silence an annoying message
+            # "hint: Using 'master' as the name for the initial branch."
+            # (cf. <https://stackoverflow.com/questions/65524512/>).
+            git -C "$gnulib_path" -c init.defaultBranch=master init
            git -C "$gnulib_path" remote add origin "$gnulib_url"
            if git -C "$gnulib_path" fetch $shallow origin "$GNULIB_REVISION"
            then
@ -864,7 +861,8 @@ autopull()
    elif check_exists git-merge-changelog; then
      echo "$0: initializing git-merge-changelog driver"
      git config merge.merge-changelog.name 'GNU-style ChangeLog merge driver'
-      git config merge.merge-changelog.driver 'git-merge-changelog %O %A %B'
+      git config merge.merge-changelog.driver \
+          'git-merge-changelog %O %A %B "%Y"'
    else
      echo "$0: consider installing git-merge-changelog from gnulib"
    fi
@ -1340,7 +1338,7 @@ autogen()

  # Invoke autoreconf with --force --install to ensure upgrades of tools
  # such as ylwrap.
-  AUTORECONFFLAGS="--verbose --install --force -I $m4_base $ACLOCAL_FLAGS"
+  AUTORECONFFLAGS="--verbose --install --force $ACLOCAL_FLAGS"
  AUTORECONFFLAGS="$AUTORECONFFLAGS --no-recursive"

  # Tell autoreconf not to invoke autopoint or libtoolize; they were run above.
@ -1416,7 +1414,7 @@ autogen()
 # Local Variables:
 # eval: (add-hook 'before-save-hook 'time-stamp nil t)
 # time-stamp-start: "scriptlibversion="
-# time-stamp-format: "%:y-%02m-%02d.%02H"
+# time-stamp-format: "%Y-%02m-%02d.%02H"
 # time-stamp-time-zone: "UTC0"
 # time-stamp-end: "; # UTC"
 # End:
@ -1627,7 +1625,7 @@ fi
 # Local Variables:
 # eval: (add-hook 'before-save-hook 'time-stamp nil t)
 # time-stamp-start: "scriptversion="
-# time-stamp-format: "%:y-%02m-%02d.%02H"
+# time-stamp-format: "%Y-%02m-%02d.%02H"
 # time-stamp-time-zone: "UTC0"
 # time-stamp-end: "; # UTC"
 # End:
--- a/bootstrap.conf
+++ b/bootstrap.conf
@ -1,6 +1,6 @@
 # Bootstrap configuration.

-# Copyright (C) 2006-2013, 2015-2025 Free Software Foundation, Inc.
+# Copyright (C) 2006-2013, 2015-2026 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
@ -16,12 +16,31 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.

 avoided_gnulib_modules='
-  --avoid=localename
+  --avoid=hard-locale
+  --avoid=localename-unsafe
+  --avoid=localename-unsafe-limited
  --avoid=lock-tests
  --avoid=mbuiter
  --avoid=mbuiterf
  --avoid=setlocale
 '
+# These tests depend on localcharset, which we avoid.
+avoided_gnulib_tests='
+  --avoid=c32width-tests
+  --avoid=quotearg-simple-tests
+  --avoid=regex-tests
+  --avoid=wcwidth-tests
+'
+# These test whether all bytes are valid in the C locale,
+# which we don't care about.
+avoided_gnulib_tests=$avoided_gnulib_tests'
+  --avoid=btoc32-tests
+  --avoid=btowc-tests
+  --avoid=mbrtoc32-tests
+  --avoid=mbrtowc-tests
+  --avoid=mbsrtoc32s-tests
+  --avoid=mbsrtowcs-tests
+'

 # gnulib modules used by this package.
 gnulib_modules='
@ -66,7 +85,6 @@ gnu-make
 gnu-web-doc-update
 gnumakefile
 gnupload
-hard-locale
 ialloc
 idx
 intprops
@ -81,7 +99,7 @@ mempcpy
 minmax
 mkstemp
 mktime
-nstrftime
+nstrftime-limited
 nullptr
 openat
 pclose
@ -105,8 +123,9 @@ stat
 stat-macros
 stat-size
 stat-time
-stdckdint-h
 stdc_bit_width
+stdckdint-h
+stdcountof-h
 stdint-h
 stpcpy
 strcase
@ -149,6 +168,7 @@ gnulib_tool_option_extras="--tests-base=gnulib-tests
 --symlink
 --makefile-name=gnulib.mk
 $avoided_gnulib_modules
+ $avoided_gnulib_tests
 "

 # Build prerequisites
--- a/cfg.mk
+++ b/cfg.mk
@ -1,5 +1,5 @@
 # Customize maint.mk                           -*- makefile -*-
-# Copyright (C) 2003-2013, 2015-2025 Free Software Foundation, Inc.
+# Copyright (C) 2003-2013, 2015-2026 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
@ -36,7 +36,7 @@ announcement_Cc_ = $(translation_project_), $(PACKAGE)-devel@gnu.org
 # Now that we have better tests, make this the default.
 export VERBOSE = yes

-old_NEWS_hash = d6a8096805f9b3ee162842058477f0bc
+old_NEWS_hash = cfdcec044a361bf0e7b4e860bacc3d53

 # Tell maint.mk's syntax-check rules that diff gets config.h directly or
 # via diff.h or system.h.
@ -85,3 +85,5 @@ exclude_file_name_regexp--sc_prohibit_strcmp = ^gl/lib/
 # Tell gnulib's tight_scope rule that we mark extern inlines with
 # DIFF_INLINE and SYSTEM_INLINE.
 export _gl_TS_extern = extern|DIFF_INLINE|SYSTEM_INLINE
+
+codespell_ignore_words_list = FO,ND,debbugs
--- a/configure.ac
+++ b/configure.ac
@ -1,6 +1,6 @@
 # Configure template for GNU Diffutils.

-# Copyright (C) 1994-1995, 1998, 2001-2002, 2004, 2006, 2009-2013, 2015-2025
+# Copyright (C) 1994-1995, 1998, 2001-2002, 2004, 2006, 2009-2013, 2015-2026
 # Free Software Foundation, Inc.

 # This program is free software: you can redistribute it and/or modify
@ -37,6 +37,18 @@ AC_PROG_AWK
 AC_PROG_CC
 AM_MISSING_PROG([HELP2MAN], [help2man])
 AC_PROG_RANLIB
+
+# Do not worry about multibyte C locales.
+# This removes dependencies on hard-locale etc.
+gl_cv_func_mbrtowc_C_locale_sans_EILSEQ="guessing yes"
+gl_cv_func_mbrtoc32_C_locale_sans_EILSEQ="guessing yes"
+
+# Default Gnulib configuration to no multithreading,
+# since diffutils is single-threaded.
+# Although the builder can override this with the --enable-threads option
+# of 'configure', diffutils does not support that on all platforms.
+m4_define([gl_THREADLIB_DEFAULT_NO])
+
 gl_EARLY
 gl_USE_SYSTEM_EXTENSIONS
 gl_INIT
@ -59,6 +71,15 @@ AC_DEFINE([GNULIB_MBRTOC32_REGULAR], [1],
  [Do not worry about rare encodings like CP864, EBCDIC, Johab, and Shift JIS
   that glibc does not support.])

+AC_DEFINE([REQUIRE_GNUISH_STRFTIME_AM_PM], [0],
+  [Do not worry about GNU strftime behavior for AM and PM indicators.])
+AC_DEFINE([SUPPORT_NON_GREG_CALENDARS_IN_STRFTIME], [false],
+  [Do not worry about GNU strftime behavior for non-Gregorian calendars.])
+
+# Diffutils translates Gnulib's msgids too.
+AC_DEFINE([GNULIB_TEXT_DOMAIN], [PACKAGE],
+  [Textdomain to use when translating Gnulib's msgids.])
+
 AC_C_INLINE

 AC_CHECK_MEMBERS([struct stat.st_rdev])
@ -66,10 +87,6 @@ AC_HEADER_DIRENT
 AC_HEADER_SYS_WAIT
 AC_TYPE_PID_T

-AC_CHECK_FUNCS_ONCE([sigaction sigprocmask])
-if test $ac_cv_func_sigprocmask = no; then
-  AC_CHECK_FUNCS([sigblock])
-fi
 AC_FUNC_FORK

 dnl O_PATH exists since Linux 2.6.39, but is supported with fstat() only since
@ -184,8 +201,8 @@ AC_DEFINE_UNQUOTED([PR_PROGRAM], ["$PR_PROGRAM"], [Name of "pr" program.])

 # When .tarball-version exists, we're building from a tarball
 # and must not make man/*.1 files depend on the generated src/version.c,
-# because that would induce a requirement to run the help2man perl script.
-# We are not yet prepared to make perl a build-from-tarball requirement.
+# because that would induce a requirement to run help2man.
+# We are not yet prepared to make help2man a build-from-tarball requirement.
 # Hence, here we detect .tarball-version existence.  When not present,
 # we define a variable to be used in man/Makefile.am to induce the
 # proper dependency (so that man/*.1 will be rebuilt upon any version change),
@ -195,7 +212,7 @@ test -f $srcdir/.tarball-version \
  && SRC_VERSION_C= \
  || SRC_VERSION_C=../src/version.c

-AM_GNU_GETTEXT([external], [need-ngettext])
+AM_GNU_GETTEXT([external], [need-formatstring-macros])
 AM_GNU_GETTEXT_VERSION([0.19.2])
 XGETTEXT="AWK='$AWK' \$(SHELL) \$(top_srcdir)/exgettext $XGETTEXT"

--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@ -1,6 +1,6 @@
 # Makefile for GNU diffutils documentation.

-# Copyright (C) 2001-2002, 2009-2013, 2015-2025 Free Software Foundation, Inc.
+# Copyright (C) 2001-2002, 2009-2013, 2015-2026 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
--- a/doc/diffutils.texi
+++ b/doc/diffutils.texi
@ -17,7 +17,7 @@ and documents the GNU @command{diff}, @command{diff3},
 differences between files and the GNU @command{patch} command for
 using their output to update files.

-Copyright @copyright{} 1992--1994, 1998, 2001--2002, 2004, 2006, 2009--2025
+Copyright @copyright{} 1992--1994, 1998, 2001--2002, 2004, 2006, 2009--2026
 Free Software Foundation, Inc.

@quotation
@ -4016,7 +4016,7 @@ found.  @xref{Comparing Directories}.

@item -s
@itemx --report-identical-files
-Report when two files are the same.  @xref{Comparing Directories}.
+Also report when two files are the same.  @xref{Comparing Directories}.

@item -S @var{file}
@itemx --starting-file=@var{file}
--- a/doc/fdl.texi
+++ b/doc/fdl.texi
@ -5,7 +5,7 @@
@c hence no sectioning command or @node.

@display
-Copyright @copyright{} 2000--2002, 2007--2008, 2022--2025 Free Software
+Copyright @copyright{} 2000--2002, 2007--2008, 2022--2026 Free Software
 Foundation, Inc.
@uref{https://fsf.org/}

--- a/2
+++ b/2
@ -1,7 +1,7 @@
 #! /bin/sh
 # Wrapper around gettext for programs using the msgid convention.

-# Copyright (C) 1998, 2001, 2004, 2009-2013, 2015-2025 Free Software
+# Copyright (C) 1998, 2001, 2004, 2009-2013, 2015-2026 Free Software
 # Foundation, Inc.

 # Written by Paul Eggert <eggert@twinsun.com>.
--- a/2
+++ b/2
@ -1 +1 @@
-Subproject commit 553ab924d2b68d930fae5d3c6396502a57852d23
+Subproject commit 4f6ac2c3c689cd7312b5f9da97791b14bbc2ee53
--- a/gnulib-tests/Makefile.am
+++ b/gnulib-tests/Makefile.am
@ -1 +1,3 @@
+AM_CFLAGS =
+
 include gnulib.mk
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@ -1,6 +1,6 @@
 # Automakefile for GNU Diffutils library.

-# Copyright (C) 2001-2002, 2004, 2006, 2009-2013, 2015-2025 Free Software
+# Copyright (C) 2001-2002, 2004, 2006, 2009-2013, 2015-2026 Free Software
 # Foundation, Inc.

 # This program is free software: you can redistribute it and/or modify
--- a/lib/cmpbuf.c
+++ b/lib/cmpbuf.c
@ -1,6 +1,6 @@
 /* Buffer primitives for comparison operations.

-   Copyright (C) 1993, 1995, 1998, 2001-2002, 2006, 2009-2013, 2015-2025 Free
+   Copyright (C) 1993, 1995, 1998, 2001-2002, 2006, 2009-2013, 2015-2026 Free
   Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify
--- a/lib/cmpbuf.h
+++ b/lib/cmpbuf.h
@ -1,6 +1,6 @@
 /* Buffer primitives for comparison operations.

-   Copyright (C) 2002, 2009-2013, 2015-2025 Free Software Foundation, Inc.
+   Copyright (C) 2002, 2009-2013, 2015-2026 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
--- a/lib/diagnose.c
+++ b/lib/diagnose.c
@ -1,6 +1,6 @@
 /* Diagnostics for GNU diffutils

-   Copyright 2023-2025 Free Software Foundation, Inc.
+   Copyright 2023-2026 Free Software Foundation, Inc.

   This file is part of GNU DIFF.

--- a/man/Makefile.am
+++ b/man/Makefile.am
@ -1,6 +1,6 @@
 # Automakefile for GNU diffutils man pages

-# Copyright (C) 2002, 2009-2013, 2015-2025 Free Software Foundation, Inc.
+# Copyright (C) 2002, 2009-2013, 2015-2026 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
@ -16,7 +16,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.

 dist_man1_MANS = cmp.1 diff.1 diff3.1 sdiff.1
-EXTRA_DIST = $(dist_man1_MANS:%.1=%.x) help2man
+EXTRA_DIST = $(dist_man1_MANS:%.1=%.x)
 MAINTAINERCLEANFILES = $(dist_man1_MANS)

 S = $(top_srcdir)/src
@ -29,13 +29,13 @@ sdiff.1: $S/sdiff.c sdiff.x
 # to ensure help2man invokes them via the use of PATH below.
 bin_dir = ../src

-# Depend on the former to get version number changes.
-$(dist_man1_MANS): $(SRC_VERSION_C) help2man
+# Depend on $(SRC_VERSION_C) to get version number changes.
+$(dist_man1_MANS): $(SRC_VERSION_C)
 	$(AM_V_GEN)base=`expr $@ : '\(.*\).1'`				\
 	  && test -x $(bin_dir)/$$base					\
 	  && (echo '[NAME]'						\
 	      && sed 's@/\* *@@; s/-/\\-/;s/^GNU //; q' $S/$$base.c)	\
 	     | PATH="$(bin_dir)$(PATH_SEPARATOR)$$PATH"			\
-	       $(srcdir)/help2man -i - -i $(srcdir)/$$base.x		\
+	       $(HELP2MAN) -i - -i $(srcdir)/$$base.x			\
 		 -S '$(PACKAGE) $(VERSION)' $$base > $$base.1-t		\
 	  && mv $$base.1-t $(srcdir)/$$base.1
--- a/man/help2man
+++ b/man/help2man
@ -1,801 +0,0 @@
-#!/usr/bin/env perl
-
-# Generate a short man page from --help and --version output.
-# Copyright (C) 1997-2005, 2009-2017, 2020-2021, 2025 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, 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 <https://www.gnu.org/licenses/>.
-
-# Written by Brendan O'Dea <bod@debian.org>
-# Available from https://ftp.gnu.org/gnu/help2man/
-
-use 5.008;
-use strict;
-use warnings;
-use Getopt::Long;
-use Text::ParseWords qw(shellwords);
-use Text::Tabs qw(expand);
-use POSIX qw(strftime setlocale LC_ALL);
-
-my $this_program = 'help2man';
-my $this_version = '1.48.5';
-
-sub _ { $_[0] }
-sub configure_locale
-{
-    my $locale = shift;
-    die "$this_program: no locale support (Locale::gettext required)\n"
-	unless $locale eq 'C';
-}
-
-sub dec { $_[0] }
-sub enc { $_[0] }
-sub enc_user { $_[0] }
-sub kark { die +(sprintf shift, @_), "\n" }
-sub N_ { $_[0] }
-
-sub program_basename;
-sub get_option_value;
-sub convert_option;
-sub fix_italic_spacing;
-
-my $version_info = enc_user sprintf _(<<'EOT'), $this_program, $this_version;
-GNU %s %s
-
-Copyright (C) 1997-2005, 2009-2017, 2020-2021, 2025 Free Software Foundation,
-Inc.
-This is free software; see the source for copying conditions.  There is NO
-warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
-
-Written by Brendan O'Dea <bod@debian.org>
-EOT
-
-my $help_info = enc_user sprintf _(<<'EOT'), $this_program, $this_program;
-`%s' generates a man page out of `--help' and `--version' output.
-
-Usage: %s [OPTION]... EXECUTABLE
-
- -n, --name=STRING       description for the NAME paragraph
- -s, --section=SECTION   section number for manual page (1, 6, 8)
- -m, --manual=TEXT       name of manual (User Commands, ...)
- -S, --source=TEXT       source of program (FSF, Debian, ...)
- -L, --locale=STRING     select locale (default "C")
- -i, --include=FILE      include material from `FILE'
- -I, --opt-include=FILE  include material from `FILE' if it exists
- -o, --output=FILE       send output to `FILE'
- -p, --info-page=TEXT    name of Texinfo manual
- -N, --no-info           suppress pointer to Texinfo manual
- -l, --libtool           exclude the `lt-' from the program name
- -b, --bold-refs         apply bold style to references
-     --help              print this help, then exit
-     --version           print version number, then exit
-
-EXECUTABLE should accept `--help' and `--version' options and produce output on
-stdout although alternatives may be specified using:
-
- -h, --help-option=STRING     help option string
- -v, --version-option=STRING  version option string
- --version-string=STRING      version string
- --no-discard-stderr          include stderr when parsing option output
-
-Report bugs to <bug-help2man@gnu.org>.
-EOT
-
-my $section = 1;
-my $manual = '';
-my $source = '';
-my $help_option = '--help';
-my $version_option = '--version';
-my $discard_stderr = 1;
-my ($opt_name, @opt_include, $opt_output, $opt_info, $opt_no_info, $opt_libtool,
-    $opt_bold_refs, $version_text);
-
-my %opt_def = (
-    'n|name=s'		 => \$opt_name,
-    's|section=s'	 => \$section,
-    'm|manual=s'	 => \$manual,
-    'S|source=s'	 => \$source,
-    'L|locale=s'	 => sub { configure_locale pop },
-    'i|include=s'	 => sub { push @opt_include, [ pop, 1 ] },
-    'I|opt-include=s'	 => sub { push @opt_include, [ pop, 0 ] },
-    'o|output=s'	 => \$opt_output,
-    'p|info-page=s'	 => \$opt_info,
-    'N|no-info'		 => \$opt_no_info,
-    'l|libtool'		 => \$opt_libtool,
-    'b|bold-refs'	 => \$opt_bold_refs,
-    'help'		 => sub { print $help_info; exit },
-    'version'		 => sub { print $version_info; exit },
-    'h|help-option=s'	 => \$help_option,
-    'v|version-option=s' => \$version_option,
-    'version-string=s'	 => \$version_text,
-    'discard-stderr!'	 => \$discard_stderr,
-);
-
-# Parse options.
-Getopt::Long::config('bundling');
-die $help_info unless GetOptions %opt_def and @ARGV == 1;
-
-my %include = ();
-my %replace = ();
-my %append = ();
-my %append_match = ();
-my @sections = ();  # retain order of include file or in-line *section*s
-
-# Process include file (if given).  Format is:
-#
-#   Optional initial text, ignored.  May include lines starting with `-'
-#   which are processed as options.
-#
-#   [section]
-#   Verbatim text to be included in the named section.  By default at
-#   the start, but in the case of `name' and `synopsis' the content
-#   will replace the autogenerated contents.
-#
-#   [<section]
-#   Verbatim text to be inserted at the start of the named section.
-#
-#   [=section]
-#   Verbatim text to replace the named section.
-#
-#   [>section]
-#   Verbatim text to be appended to the end of the named section.
-#
-#   /pattern/
-#   Verbatim text for inclusion below a paragraph matching `pattern'.
-#
-
-while (@opt_include)
-{
-    my ($inc, $required) = @{shift @opt_include};
-
-    next unless -f $inc or $required;
-    kark N_("%s: can't open `%s' (%s)"), $this_program, $inc, $!
-	unless open INC, $inc;
-
-    my $key;
-    my $hash;
-
-    while (<INC>)
-    {
-	# Convert input to internal Perl format, so that multibyte
-	# sequences are treated as single characters.
-	$_ = dec $_;
-
-	# [section]
-	if (/^\[([^]]+)\]\s*$/)
-	{
-	    $key = uc $1;
-	    $key =~ s/^\s+//;
-	    $key =~ s/\s+$//;
-	    $hash = \%include;
-	    # Handle explicit [<section], [=section] and [>section]
-	    if ($key =~ s/^([<>=])\s*//)
-	    {
-		if    ($1 eq '>') { $hash = \%append; }
-		elsif ($1 eq '=') { $hash = \%replace; }
-	    }
-	    # NAME/SYNOPSIS replace by default
-	    elsif ($key eq _('NAME') or $key eq _('SYNOPSIS'))
-	    {
-		$hash = \%replace;
-	    }
-	    else
-	    {
-		$hash = \%include;
-	    }
-
-	    push @sections, $key;
-	    next;
-	}
-
-	# /pattern/
-	if (m!^/(.*)/([ims]*)\s*$!)
-	{
-	    my $pat = $2 ? "(?$2)$1" : $1;
-
-	    # Check pattern.
-	    eval { $key = qr($pat) };
-	    if ($@)
-	    {
-		$@ =~ s/ at .*? line \d.*//;
-		die "$inc:$.:$@";
-	    }
-
-	    $hash = \%append_match;
-	    next;
-	}
-
-	# Check for options before the first section--anything else is
-	# silently ignored, allowing the first for comments and
-	# revision info.
-	unless ($key)
-	{
-	    # handle options
-	    if (/^-/)
-	    {
-		local @ARGV = shellwords $_;
-		GetOptions %opt_def;
-	    }
-
-	    next;
-	}
-
-	$hash->{$key} .= $_;
-    }
-
-    close INC;
-
-    kark N_("%s: no valid information found in `%s'"), $this_program, $inc
-	unless $key;
-}
-
-# Compress trailing blank lines.
-for my $hash (\(%include, %replace, %append, %append_match))
-{
-    for (keys %$hash) { $hash->{$_} =~ s/\n+$/\n/ }
-}
-
-# Grab help and version info from executable.
-my $help_text   = get_option_value $ARGV[0], $help_option;
-$version_text ||= get_option_value $ARGV[0], $version_option;
-
-# By default the generated manual pages will include the current date.  This may
-# however be overridden by setting the environment variable $SOURCE_DATE_EPOCH
-# to an integer value of the seconds since the UNIX epoch.  This is primarily
-# intended to support reproducible builds (wiki.debian.org/ReproducibleBuilds)
-# and will additionally ensure that the output date string is UTC.
-my $epoch_secs = time;
-if (exists $ENV{SOURCE_DATE_EPOCH} and $ENV{SOURCE_DATE_EPOCH} =~ /^(\d+)$/)
-{
-    $epoch_secs = $1;
-    $ENV{TZ} = 'UTC0';
-}
-
-# Translators: the following message is a strftime(3) format string, which in
-# the English version expands to the month as a word and the full year.  It
-# is used on the footer of the generated manual pages.  If in doubt, you may
-# just use %x as the value (which should be the full locale-specific date).
-my $date = enc strftime _("%B %Y"), localtime $epoch_secs;
-my $program = program_basename $ARGV[0];
-my $package = $program;
-my $version;
-
-if ($opt_output)
-{
-    unlink $opt_output or kark N_("%s: can't unlink %s (%s)"),
-	$this_program, $opt_output, $! if -e $opt_output;
-
-    open STDOUT, ">$opt_output"
-	or kark N_("%s: can't create %s (%s)"), $this_program, $opt_output, $!;
-}
-
-# The first line of the --version information is assumed to be in one
-# of the following formats:
-#
-#   <version>
-#   <program> <version>
-#   {GNU,Free} <program> <version>
-#   <program> ({GNU,Free,} <package>) <version>
-#   <program> - {GNU,Free,} <package> <version>
-#   <program> - {GNU,Free,} <package> - <version>
-#
-# and separated from any copyright/author details by a blank line.
-
-($_, $version_text) = ((split /\n+/, $version_text, 2), '');
-
-if (/^(\S+) +\(((?:(?:GNU|Free) +)?[^)]+)\) +(\S.*)$/ or
-    /^(\S+) +- +((?:(?:GNU|Free) +)?\S.*) +- +(\S.*)$/ or
-    /^(\S+) +- +((?:(?:GNU|Free) +)?\S+) +(\S.*)$/)
-{
-    $program = program_basename $1;
-    $package = $2;
-    $version = $3;
-}
-elsif (/^((?:GNU|Free) +)?(\S+) +(\S.*)$/)
-{
-    $program = program_basename $2;
-    $package = $1 ? "$1$program" : $program;
-    $version = $3;
-}
-else
-{
-    $version = $_;
-}
-
-# No info for `info' itself.
-$opt_no_info = 1 if $program eq 'info';
-
-if ($opt_name)
-{
-    # --name overrides --include contents.
-    $replace{_('NAME')} = "$program \\- $opt_name\n";
-}
-
-# Translators: "NAME", "SYNOPSIS" and other one or two word strings in all
-# upper case are manual page section headings.  The man(1) manual page in your
-# language, if available should provide the conventional translations.
-for ($replace{_('NAME')} || ($include{_('NAME')} ||= ''))
-{
-    if ($_) # Use first name given as $program
-    {
-	$program = $1 if /^([^\s,]+)(?:,?\s*[^\s,\\-]+)*\s+\\?-/;
-    }
-    else # Set a default (useless) NAME paragraph.
-    {
-	$_ = sprintf _("%s \\- manual page for %s %s") . "\n", $program,
-	    $program, $version;
-    }
-}
-
-# Man pages traditionally have the page title in caps.
-my $PROGRAM = uc $program;
-
-# Set default page head/footers
-$source ||= "$package $version";
-unless ($manual)
-{
-    for ($section)
-    {
-	if (/^(1[Mm]|8)/) { $manual = enc _('System Administration Utilities') }
-	elsif (/^6/)	  { $manual = enc _('Games') }
-	else		  { $manual = enc _('User Commands') }
-    }
-}
-
-# Extract usage clause(s) [if any] for SYNOPSIS.
-# Translators: "Usage" and "or" here are patterns (regular expressions) which
-# are used to match the usage synopsis in program output.  An example from cp
-# (GNU coreutils) which contains both strings:
-#  Usage: cp [OPTION]... [-T] SOURCE DEST
-#    or:  cp [OPTION]... SOURCE... DIRECTORY
-#    or:  cp [OPTION]... -t DIRECTORY SOURCE...
-my $PAT_USAGE = _('Usage');
-my $PAT_USAGE_CONT = _('or');
-if ($help_text =~ s/^($PAT_USAGE):( +(\S+))(.*)((?:\n(?: {6}\1| *($PAT_USAGE_CONT): +\S).*)*)//om)
-{
-    my @syn = $3 . $4;
-
-    if ($_ = $5)
-    {
-	s/^\n//;
-	for (split /\n/) { s/^ *(($PAT_USAGE_CONT): +)?//o; push @syn, $_ }
-    }
-
-    my $synopsis = '';
-    for (@syn)
-    {
-	$synopsis .= ".br\n" if $synopsis;
-	s!^\S*/!!;
-	s/^lt-// if $opt_libtool;
-	s/^(\S+) *//;
-	$synopsis .= ".B $1\n";
-	s/\s+$//;
-	s/(([][]|\.\.+)+)/\\fR$1\\fI/g;
-	s/^/\\fI/ unless s/^\\fR//;
-	$_ .= '\fR';
-	s/(\\fI)( *)/$2$1/g;
-	s/\\fI\\fR//g;
-	s/^\\fR//;
-	s/\\fI$//;
-	s/^\./\\&./;
-
-	$_ = fix_italic_spacing $_;
-	$synopsis .= "$_\n";
-    }
-
-    $include{_('SYNOPSIS')} .= $synopsis;
-}
-
-# Process text, initial section is DESCRIPTION.
-my $sect = _('DESCRIPTION');
-$_ = "$help_text\n\n$version_text";
-
-# Normalise paragraph breaks.
-s/^\n+//;
-s/\n*$/\n/;
-s/\n\n+/\n\n/g;
-
-# Join hyphenated lines.
-s/([A-Za-z])-\n *([A-Za-z])/$1$2/g;
-
-# Temporarily exchange leading dots, apostrophes and backslashes for
-# tokens.
-s/^\./\x80/mg;
-s/^'/\x81/mg;
-s/\\/\x82/g;
-
-# Translators: patterns are used to match common program output. In the source
-# these strings are all of the form of "my $PAT_something = _('...');" and are
-# regular expressions.  If there is more than one commonly used string, you
-# may separate alternatives with "|".  Spaces in these expressions are written
-# as " +" to indicate that more than one space may be matched.  The string
-# "(?:[\\w-]+ +)?" in the bug reporting pattern is used to indicate an
-# optional word, so that either "Report bugs" or "Report _program_ bugs" will
-# be matched.
-my $PAT_BUGS          = _('Report +(?:[\w-]+ +)?bugs|' .
-                          'Email +bug +reports +to|' .
-                          '.* +online +help:');
-my $PAT_AUTHOR        = _('Written +by');
-my $PAT_OPTIONS       = _('Options');
-my $PAT_ENVIRONMENT   = _('Environment');
-my $PAT_FILES         = _('Files');
-my $PAT_EXAMPLES      = _('Examples');
-my $PAT_FREE_SOFTWARE = _('This +is +free +software');
-my $PAT_SEE_ALSO      = _('Full +documentation');
-
-# Start a new paragraph (if required) for these.
-s/([^\n])\n($PAT_BUGS|$PAT_AUTHOR|$PAT_SEE_ALSO) /$1\n\n$2 /og;
-
-# Convert iso-8859-1 copyright symbol or (c) to nroff
-# character.
-s/^Copyright +(?:\xa9|\([Cc]\))/Copyright \\(co/mg;
-
-while (length)
-{
-    # Convert some standard paragraph names.
-    if (s/^($PAT_OPTIONS): *\n+//o)
-    {
-	$sect = _('OPTIONS');
-	next;
-    }
-    if (s/^($PAT_ENVIRONMENT): *\n+//o)
-    {
-	$sect = _('ENVIRONMENT');
-	next;
-    }
-    if (s/^($PAT_FILES): *\n+//o)
-    {
-	$sect = _('FILES');
-	next;
-    }
-    elsif (s/^($PAT_EXAMPLES): *\n+//o)
-    {
-	$sect = _('EXAMPLES');
-	next;
-    }
-
-    # Custom section indicated by a line containing "*Section Name*".
-    if (s/^\*(\w(.*\w)?)\* *\n+//)
-    {
-	$sect = uc $1;
-	$sect =~ tr/*/ /;  # also accept *Section*Name*
-	push @sections, $sect;
-	next;
-    }
-
-    # Copyright section.
-    if (/^Copyright /)
-    {
-	$sect = _('COPYRIGHT');
-    }
-
-    # Bug reporting section.
-    elsif (/^($PAT_BUGS) /o)
-    {
-	$sect = _('REPORTING BUGS');
-    }
-
-    # Author section.
-    elsif (/^($PAT_AUTHOR)/o)
-    {
-	$sect = _('AUTHOR');
-    }
-
-    elsif (/^($PAT_SEE_ALSO)/o)
-    {
-	$sect = _('SEE ALSO');
-	$opt_no_info = 1;
-    }
-
-    # Examples, indicated by an indented leading $, % or > are
-    # rendered in a constant width font.
-    if (/^( +)([\$\%>] )\S/)
-    {
-	my $indent = $1;
-	my $prefix = $2;
-	my $break = '.IP';
-	while (s/^$indent\Q$prefix\E(\S.*)\n*//)
-	{
-	    $include{$sect} .= "$break\n\\f(CW$prefix$1\\fR\n";
-	    $break = '.br';
-	}
-
-	next;
-    }
-
-    my $matched = '';
-
-    # Sub-sections have a trailing colon and the second line indented.
-    if (s/^(\S.*:) *\n / /)
-    {
-	$matched .= $& if %append_match;
-	$include{$sect} .= qq(.SS "$1"\n);
-    }
-
-    my $indent = 0;
-    my $content = '';
-
-    # Option with description.
-    if (s/^( {1,10}([+-]\S.*?))(?:(  +(?!-))|\n( {20,}))(\S.*)\n//)
-    {
-	$matched .= $& if %append_match;
-	$indent = length ($4 || "$1$3");
-	$content = ".TP\n\x84$2\n\x84$5\n";
-	unless ($4)
-	{
-	    # Indent may be different on second line.
-	    $indent = length $& if /^ {20,}/;
-	}
-    }
-
-    # Option without description.
-    elsif (s/^ {1,10}([+-]\S.*)\n//)
-    {
-	$matched .= $& if %append_match;
-	$content = ".HP\n\x84$1\n";
-	$indent = 80; # not continued
-    }
-
-    # Indented paragraph with tag.
-    elsif (s/^( +(\S.*?)  +)(\S.*)\n//)
-    {
-	$matched .= $& if %append_match;
-	$indent = length $1;
-	$content = ".TP\n\x84$2\n\x84$3\n";
-    }
-
-    # Indented paragraph.
-    elsif (s/^( +)(\S.*)\n//)
-    {
-	$matched .= $& if %append_match;
-	$indent = length $1;
-	$content = ".IP\n\x84$2\n";
-    }
-
-    # Left justified paragraph.
-    else
-    {
-	s/(.*)\n//;
-	$matched .= $& if %append_match;
-	$content = ".PP\n" if $include{$sect};
-	$content .= "$1\n";
-    }
-
-    # Append continuations.
-    while ($indent ? s/^ {$indent}(\S.*)\n// : s/^(\S.*)\n//)
-    {
-	$matched .= $& if %append_match;
-	$content .= "\x84$1\n";
-    }
-
-    # Move to next paragraph.
-    s/^\n+//;
-
-    for ($content)
-    {
-	# Leading dot and apostrophe protection.
-	s/\x84\./\x80/g;
-	s/\x84'/\x81/g;
-	s/\x84//g;
-
-	# Examples should be verbatim.
-	unless ($sect eq _('EXAMPLES'))
-	{
-	    # Convert options.
-	    s/(^|[ (])(-[][\w=-]+)/$1 . convert_option $2/mge;
-
-	    # Italicise filenames: /a/b, $VAR/c/d, ~/e/f
-	    s!
-		(^|[ (])			# space/punctuation before
-		(
-		    (?:\$\w+|~)?		# leading variable, or tilde
-		    (?:/\w(?:[\w.-]*\w)?)+	# path components
-		)
-		($|[ ,;.)])			# space/punctuation after
-	    !$1\\fI$2\\fP$3!xmg;
-
-	    $_ = fix_italic_spacing $_;
-	}
-
-	# Escape remaining hyphens.
-	s/-/\x83/g;
-
-	if ($sect eq _('COPYRIGHT'))
-	{
-	    # Insert line breaks before additional copyright messages
-	    # and the disclaimer.
-	    s/\n(Copyright |$PAT_FREE_SOFTWARE)/\n.br\n$1/og;
-	}
-	elsif ($sect eq _('REPORTING BUGS'))
-	{
-	    # Handle multi-line bug reporting sections of the form:
-	    #
-	    #   Report <program> bugs to <addr>
-	    #   GNU <package> home page: <url>
-	    #   ...
-	    s/\n([[:upper:]])/\n.br\n$1/g;
-	}
-	elsif ($sect eq _('SEE ALSO'))
-	{
-	    # Handle external references of the form:
-	    #
-	    #   GNU <package> online resources: <addr>
-	    #   Full documentation at: <addr>
-	    #   or available locally via: info ...
-	    #
-	    s/\'/\\(aq/g;			# shell quotes for info command
-	    s/\n(.)/\n.br\n$1/g;		# separate lines for each item
-	}
-    }
-
-    # Check if matched paragraph contains /pat/.
-    if (%append_match)
-    {
-	for my $pat (keys %append_match)
-	{
-	    if ($matched =~ $pat)
-	    {
-		$content .= ".PP\n" unless $append_match{$pat} =~ /^\./;
-		$content .= $append_match{$pat};
-	    }
-	}
-    }
-
-    $include{$sect} .= $content;
-}
-
-# Refer to the real documentation.
-unless ($opt_no_info)
-{
-    my $info_page = $opt_info || $program;
-
-    $sect = _('SEE ALSO');
-    $include{$sect} .= ".PP\n" if $include{$sect};
-    $include{$sect} .= sprintf _(<<'EOT'), $program, $program, $info_page;
-The full documentation for
-.B %s
-is maintained as a Texinfo manual.  If the
-.B info
-and
-.B %s
-programs are properly installed at your site, the command
-.IP
-.B info %s
-.PP
-should give you access to the complete manual.
-EOT
-}
-
-# Append additional text.
-while (my ($sect, $text) = each %append)
-{
-    $include{$sect} .= $append{$sect};
-}
-
-# Replace sections.
-while (my ($sect, $text) = each %replace)
-{
-    $include{$sect} = $replace{$sect};
-}
-
-# Output header.
-print <<EOT;
-.\\" DO NOT MODIFY THIS FILE!  It was generated by $this_program $this_version.
-.TH $PROGRAM "$section" "$date" "$source" "$manual"
-EOT
-
-# Section ordering.
-my @pre = (_('NAME'), _('SYNOPSIS'), _('DESCRIPTION'), _('OPTIONS'),
-    _('EXAMPLES'));
-my @post = (_('ENVIRONMENT'), _('FILES'), _('AUTHOR'),
-    _('REPORTING BUGS'), _('COPYRIGHT'), _('SEE ALSO'));
-my %filter = map { $_ => 1 } @pre, @post;
-
-# Output content.
-my %done;
-for my $sect (@pre, (grep !$filter{$_}, @sections), @post)
-{
-    next if $done{$sect}++;  # ignore duplicates
-    next unless $include{$sect};
-    if ($include{$sect})
-    {
-	my $quote = $sect =~ /\W/ ? '"' : '';
-	print enc ".SH $quote$sect$quote\n";
-
-	for ($include{$sect})
-	{
-            # Add bold style around referenced pages.
-            if ($opt_bold_refs)
-            {
-                # This will ignore entries already marked up (with \)
-                s/(^|\s|,)([\[\w\x83]+)\(([1-9][[:lower:]]?)\)/$1\\fB$2\\fP($3)/g;
-            }
-
-	    # Replace leading dot, apostrophe, backslash and hyphen
-	    # tokens.
-	    s/\x80/\\&./g;
-	    s/\x81/\\&'/g;
-	    s/\x82/\\e/g;
-	    s/\x83/\\-/g;
-
-	    # Convert some latin1 chars to troff equivalents
-	    s/\xa0/\\ /g; # non-breaking space
-
-	    print enc $_;
-	}
-    }
-}
-
-close STDOUT or kark N_("%s: error writing to %s (%s)"), $this_program,
-    $opt_output || 'stdout', $!;
-
-exit;
-
-# Get program basename, and strip libtool "lt-" prefix if required.
-sub program_basename
-{
-    local $_ = shift;
-    s!.*/!!;
-    s/^lt-// if $opt_libtool;
-    $_;
-}
-
-# Call program with given option and return results.
-sub get_option_value
-{
-    my ($prog, $opt) = @_;
-    my $stderr = $discard_stderr ? '/dev/null' : '&1';
-    my $value = join '',
-	map { s/ +$//; expand $_ }
-	map { dec $_ }
-	`$prog $opt 2>$stderr`;
-
-    unless ($value)
-    {
-	my $err = N_("%s: can't get `%s' info from %s%s");
-	my $extra = $discard_stderr
-	    ? "\n" . N_("Try `--no-discard-stderr' if option outputs to stderr")
-	    : '';
-
-	kark $err, $this_program, $opt, $prog, $extra;
-    }
-
-    $value;
-}
-
-# Convert option dashes to \- to stop nroff from hyphenating 'em, and
-# embolden.  Option arguments get italicised.
-sub convert_option
-{
-    local $_ = '\fB' . shift;
-
-    s/-/\x83/g;
-    unless (s/\[=(.*)\]$/\\fR[=\\fI$1\\fR]/)
-    {
-	s/=(.)/\\fR=\\fI$1/;
-	s/ (.)/ \\fI$1/;
-	$_ .= '\fR';
-    }
-
-    $_;
-}
-
-# Insert spacing escape characters \, and \/ before and after italic text.  See
-# https://www.gnu.org/software/groff/manual/html_node/Ligatures-and-Kerning.html
-sub fix_italic_spacing
-{
-    local $_ = shift;
-    s!\\fI(.*?)\\f([BRP])!\\fI\\,$1\\/\\f$2!g;
-    return $_;
-}
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@ -1,6 +1,6 @@
 # List of files that contain translatable strings.

-# Copyright (C) 2001-2002, 2009-2013, 2015-2025 Free Software Foundation, Inc.
+# Copyright (C) 2001-2002, 2009-2013, 2015-2026 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
--- a/po/en.po
+++ b/po/en.po
@ -1,30 +0,0 @@
-# English messages for GNU diffutils
-# Copyright 1998, 2001-2003, 2009-2013, 2015-2025 Free Software Foundation,
-# Inc.
-# Paul Eggert <eggert@twinsun.com>, 1998
-#
-msgid ""
-msgstr ""
-"Project-Id-Version: GNU diffutils 3.2\n"
-"POT-Creation-Date: 2002-06-16 23:44-0700\n"
-"PO-Revision-Date: 2012-01-25 23:11-0700\n"
-"Last-Translator: Paul Eggert <eggert@cs.ucla.edu>\n"
-"Language-Team: English <en@translate.freefriends.org>\n"
-"MIME-Version: 1.0\n"
-"Content-Type: text/plain; charset=UTF-8\n"
-"Content-Transfer-Encoding: 8bit\n"
-
-#. TRANSLATORS: Please translate "(C)" to the C-in-a-circle symbol
-#. (U+00A9, COPYRIGHT SIGN) if possible, as this has some minor
-#. technical advantages in international copyright law.  If the
-#. copyright symbol is not available, please leave it as "(C)".
-#: lib/version-etc.c:50
-msgid "(C)"
-msgstr "©"
-
-#. TRANSLATORS: Please translate the second "o" in "Torbjorn Granlund"
-#. to an o-with-umlaut (U+00F6, LATIN SMALL LETTER O WITH DIAERESIS)
-#. if possible.
-#: src/cmp.c:47
-msgid "Written by Torbjorn Granlund and David MacKenzie."
-msgstr "Written by Torbjörn Granlund and David MacKenzie."
--- a/src/Makefile.am
+++ b/src/Makefile.am
@ -1,6 +1,6 @@
 # Automakefile for GNU diffutils programs.

-# Copyright (C) 2001-2002, 2006, 2009-2013, 2015-2025 Free Software Foundation,
+# Copyright (C) 2001-2002, 2006, 2009-2013, 2015-2026 Free Software Foundation,
 # Inc.

 # This program is free software: you can redistribute it and/or modify
@ -47,8 +47,8 @@ diff3_SOURCES = diff3.c system.c
 sdiff_SOURCES = sdiff.c system.c
 diff_SOURCES = \
  analyze.c context.c diff.c dir.c ed.c ifdef.c io.c \
-  normal.c side.c system.c util.c
-noinst_HEADERS = diff.h system.h
+  normal.c side.c syncsig.c system.c util.c
+noinst_HEADERS = diff.h syncsig.h system.h

 MOSTLYCLEANFILES = paths.h paths.ht

--- a/src/analyze.c
+++ b/src/analyze.c
@ -1,7 +1,7 @@
 /* Analyze file differences for GNU DIFF.

   Copyright (C) 1988-1989, 1992-1995, 1998, 2001-2002, 2004, 2006-2007,
-   2009-2013, 2015-2025 Free Software Foundation, Inc.
+   2009-2013, 2015-2026 Free Software Foundation, Inc.

   This file is part of GNU DIFF.

--- a/src/cmp.c
+++ b/src/cmp.c
@ -1,7 +1,7 @@
 /* GNU cmp - compare two files byte by byte

   Copyright (C) 1990-1996, 1998, 2001-2002, 2004, 2006-2007, 2009-2013,
-   2015-2025 Free Software Foundation, Inc.
+   2015-2026 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
@ -28,7 +28,6 @@
 #include <exitfail.h>
 #include <file-type.h>
 #include <getopt.h>
-#include <hard-locale.h>
 #include <progname.h>
 #include <quote.h>
 #include <unlocked-io.h>
@ -46,11 +45,15 @@ static char const PROGRAM_NAME[] = "cmp";
  proper_name_lite ("Torbjorn Granlund", "Torbj\303\266rn Granlund"), \
  _("David MacKenzie")

+/* Return true if the locale's messages might not be those of C or POSIX.  */
 static bool
 hard_locale_LC_MESSAGES (void)
 {
-#if defined LC_MESSAGES && ENABLE_NLS
-  return hard_locale (LC_MESSAGES);
+#if ENABLE_NLS
+  /* GNU diff defines ENABLE_NLS only if gettext is preinstalled, and
+     on these platforms setlocale (LC_MESSAGES, nullptr) never returns nullptr
+     and always returns "C" when in the C or POSIX locales.  */
+  return !STREQ (setlocale (LC_MESSAGES, nullptr), "C");
 #else
  return false;
 #endif
--- a/src/context.c
+++ b/src/context.c
@ -1,7 +1,7 @@
 /* Context-format output routines for GNU DIFF.

   Copyright (C) 1988-1989, 1991-1995, 1998, 2001-2002, 2004, 2006, 2009-2013,
-   2015-2025 Free Software Foundation, Inc.
+   2015-2026 Free Software Foundation, Inc.

   This file is part of GNU DIFF.

@ -72,7 +72,8 @@ print_context_label (char const *mark,

      struct tm const *tm = localtime (&ts.tv_sec);
      int nsec = ts.tv_nsec;
-      if (tm && nstrftime (buf, sizeof buf, time_format, tm, localtz, nsec))
+      if (tm
+	  && 0 <= nstrftime (buf, sizeof buf, time_format, tm, localtz, nsec))
 	fprintf (outfile, "%s %s\t%s", mark, name, buf);
      else if (TYPE_SIGNED (time_t))
        {
--- a/src/diff.c
+++ b/src/diff.c
@ -1,7 +1,7 @@
 /* GNU diff - compare files line by line

   Copyright (C) 1988-1989, 1992-1994, 1996, 1998, 2001-2002, 2004, 2006-2007,
-   2009-2013, 2015-2025 Free Software Foundation, Inc.
+   2009-2013, 2015-2026 Free Software Foundation, Inc.

   This file is part of GNU DIFF.

@ -35,7 +35,7 @@
 #include <filenamecat.h>
 #include <fnmatch.h>
 #include <getopt.h>
-#include <hard-locale.h>
+#include <strftime.h>
 #include <progname.h>
 #include <quote.h>
 #include <sh-quote.h>
@ -293,6 +293,21 @@ exclude_options (void)
 {
  return EXCLUDE_WILDCARDS | (ignore_file_name_case ? FNM_CASEFOLD : 0);
 }
+
+/* Return true if in a hard LC_TIME locale.  */
+static bool
+hard_locale_LC_TIME (void)
+{
+  /* Use the heuristic that %c has its usual POSIX meaning.
+     This is good enough in practice.  */
+  static struct tm const tm
+    = { .tm_year = 1970 - 1900, .tm_mon = 0, .tm_mday = 1,
+	.tm_hour = 23, .tm_min = 59, .tm_sec = 59 };
+  static char const expected[] = "Thu Jan  1 23:59:59 1970";
+  char buf[sizeof expected];
+  return (nstrftime (buf, sizeof buf, "%c", &tm, 0, 0) == sizeof buf - 1
+	  && memcmp (buf, expected, sizeof buf) == 0);
+}

 int
 main (int argc, char **argv)
@ -746,7 +761,7 @@ main (int argc, char **argv)
        specify_style (OUTPUT_NORMAL);
    }

-  if (output_style != OUTPUT_CONTEXT || hard_locale (LC_TIME))
+  if (output_style != OUTPUT_CONTEXT || hard_locale_LC_TIME ())
    {
 #if defined STAT_TIMESPEC || defined STAT_TIMESPEC_NS
      time_format = "%Y-%m-%d %H:%M:%S.%N %z";
@ -965,8 +980,8 @@ check_stdout (void)

 static char const *const option_help_msgid[] = {
  N_("    --normal                  output a normal diff (the default)"),
-  N_("-q, --brief                   report only when files differ"),
-  N_("-s, --report-identical-files  report when two files are the same"),
+  N_("-q, --brief                   report only whether files differ"),
+  N_("-s, --report-identical-files  also report if two files are the same"),
  N_("-c, -C NUM, --context[=NUM]   output NUM (default 3) lines of copied context"),
  N_("-u, -U NUM, --unified[=NUM]   output NUM (default 3) lines of unified context"),
  N_("-e, --ed                      output an ed script"),
@ -1074,11 +1089,10 @@ Mandatory arguments to long options are mandatory for short options too.\n\

  for (char const *const *p = option_help_msgid;  *p;  p++)
    {
-      if (!**p)
-        putchar ('\n');
-      else
+      char const *msg = *p;
+      if (*msg)
        {
-          char const *msg = _(*p);
+	  msg = gettext (msg);
 	  for (char const *nl; (nl = strchr (msg, '\n')); msg = nl + 1)
            {
 	      fputs ("  ", stdout);
@ -1087,8 +1101,8 @@ Mandatory arguments to long options are mandatory for short options too.\n\

 	  if (*msg == ' ' || *msg == '-')
 	    fputs ("  ", stdout);
-	  puts (msg);
        }
+      puts (msg);
    }
  emit_bug_reporting_address ();
 }
@ -1222,14 +1236,14 @@ compare_prepped_files (struct comparison const *parent,
     the type is unusual, then simply report their type.
     However, at the top level do this only if one file is a symlink
     and the other is not.  */
-  if (toplevel
-      ? (!S_ISLNK (cmp->file[0].stat.st_mode)
-	 != !S_ISLNK (cmp->file[1].stat.st_mode))
-      : (cmp->file[0].filetype != cmp->file[1].filetype
-	 || ! (S_ISREG (cmp->file[0].stat.st_mode)
-	       || S_ISLNK (cmp->file[0].stat.st_mode)
-	       || S_ISCHR (cmp->file[0].stat.st_mode)
-	       || S_ISBLK (cmp->file[0].stat.st_mode))))
+  mode_t mode0 = cmp->file[0].stat.st_mode;
+  mode_t mode1 = cmp->file[1].stat.st_mode;
+  if (toplevel ? !S_ISLNK (mode0) != !S_ISLNK (mode1)
+      : S_ISREG (mode0) ? !S_ISREG (mode1)
+      : S_ISLNK (mode0) ? !S_ISLNK (mode1)
+      : S_ISCHR (mode0) ? !S_ISCHR (mode1)
+      : S_ISBLK (mode0) ? !S_ISBLK (mode1)
+      : true)
    {
      /* POSIX 1003.1-2017 says any message will do, so long as it
 	 contains the file names.  */
@ -1243,7 +1257,7 @@ compare_prepped_files (struct comparison const *parent,
    }

  /* If both files are symlinks, compare symlink contents.  */
-  if (S_ISLNK (cmp->file[0].stat.st_mode))
+  if (S_ISLNK (mode0))
    {
      /* We get here only if we are not dereferencing symlinks.  */
      dassert (no_dereference_symlinks);
@ -1294,7 +1308,7 @@ compare_prepped_files (struct comparison const *parent,
     and report file types of all other non-regular files.
     POSIX 1003.1-2017 says any message will do,
     so long as it contains the file names.  */
-  if (!toplevel && !S_ISREG (cmp->file[0].stat.st_mode))
+  if (!toplevel && !S_ISREG (mode0))
    {
      if (cmp->file[0].stat.st_rdev == cmp->file[1].stat.st_rdev)
 	return EXIT_SUCCESS;
@ -1310,7 +1324,7 @@ compare_prepped_files (struct comparison const *parent,
      for (int i = 0; i < n_num; i++)
 	sprintf (numbuf[i], "%"PRIdMAX, num[i]);

-      message ((S_ISCHR (cmp->file[0].stat.st_mode)
+      message ((S_ISCHR (mode0)
 		? ("Character special files %s (%s, %s)"
 		   " and %s (%s, %s) differ\n")
 		: ("Block special files %s (%s, %s)"
@ -1322,8 +1336,8 @@ compare_prepped_files (struct comparison const *parent,
    }

  if (files_can_be_treated_as_binary
-      && S_ISREG (cmp->file[0].stat.st_mode)
-      && S_ISREG (cmp->file[1].stat.st_mode)
+      && S_ISREG (mode0)
+      && S_ISREG (mode1)
      && cmp->file[0].stat.st_size != cmp->file[1].stat.st_size
      && 0 <= cmp->file[0].stat.st_size
      && 0 <= cmp->file[1].stat.st_size)
--- a/src/diff.h
+++ b/src/diff.h
@ -1,7 +1,7 @@
 /* Shared definitions for GNU DIFF

   Copyright (C) 1988-1989, 1991-1995, 1998, 2001-2002, 2004, 2009-2013,
-   2015-2025 Free Software Foundation, Inc.
+   2015-2026 Free Software Foundation, Inc.

   This file is part of GNU DIFF.

--- a/src/diff3.c
+++ b/src/diff3.c
@ -1,7 +1,7 @@
 /* GNU diff3 - compare three files line by line

   Copyright (C) 1988-1989, 1992-1996, 1998, 2001-2002, 2004, 2006, 2009-2013,
-   2015-2025 Free Software Foundation, Inc.
+   2015-2026 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
@ -1314,33 +1314,33 @@ output_diff3 (FILE *outputfile, struct diff3_block *diff,
           i = (oddoneout == 1 ? skew_increment[i] : i + 1))
        {
          int realfile = mapping[i];
-          lin lowt = D_LOWLINE (ptr, realfile);
-          lin hight = D_HIGHLINE (ptr, realfile);
+          lin low_t = D_LOWLINE (ptr, realfile);
+          lin high_t = D_HIGHLINE (ptr, realfile);

          fprintf (outputfile, "%d:", i + 1);
-          switch (lowt - hight)
+          switch (low_t - high_t)
            {
            case 1:
-              fprintf (outputfile, "%"pI"da\n", lowt - 1);
+              fprintf (outputfile, "%"pI"da\n", low_t - 1);
              break;
            case 0:
-              fprintf (outputfile, "%"pI"dc\n", lowt);
+              fprintf (outputfile, "%"pI"dc\n", low_t);
              break;
            default:
-              fprintf (outputfile, "%"pI"d,%"pI"dc\n", lowt, hight);
+              fprintf (outputfile, "%"pI"d,%"pI"dc\n", low_t, high_t);
              break;
            }

          if (i == dontprint) continue;

-          if (lowt <= hight)
+          if (low_t <= high_t)
            for (lin line = 0; ; line++)
              {
                fputs (line_prefix, outputfile);
                char *cp = D_RELNUM (ptr, realfile, line);
                idx_t length = D_RELLEN (ptr, realfile, line);
                fwrite (cp, sizeof (char), length, outputfile);
-                if (hight - lowt <= line)
+                if (high_t - low_t <= line)
                  {
                    if (cp[length - 1] != '\n')
                      fprintf (outputfile, "\n\\ %s\n",
--- a/src/dir.c
+++ b/src/dir.c
@ -1,7 +1,7 @@
 /* Read, sort and compare two directories.  Used for GNU DIFF.

   Copyright (C) 1988-1989, 1992-1995, 1998, 2001-2002, 2004, 2006-2007,
-   2009-2013, 2015-2025 Free Software Foundation, Inc.
+   2009-2013, 2015-2026 Free Software Foundation, Inc.

   This file is part of GNU DIFF.

--- a/src/ed.c
+++ b/src/ed.c
@ -1,7 +1,7 @@
 /* Output routines for ed-script format.

   Copyright (C) 1988-1989, 1991-1993, 1995, 1998, 2001, 2004, 2006, 2009-2013,
-   2015-2025 Free Software Foundation, Inc.
+   2015-2026 Free Software Foundation, Inc.

   This file is part of GNU DIFF.

--- a/src/ifdef.c
+++ b/src/ifdef.c
@ -1,6 +1,6 @@
 /* #ifdef-format output routines for GNU DIFF.

-   Copyright (C) 1989, 1991-1994, 2001-2002, 2004, 2006, 2009-2013, 2015-2025
+   Copyright (C) 1989, 1991-1994, 2001-2002, 2004, 2006, 2009-2013, 2015-2026
   Free Software Foundation, Inc.

   This file is part of GNU DIFF.
--- a/src/io.c
+++ b/src/io.c
@ -1,7 +1,7 @@
 /* File I/O for GNU DIFF.

   Copyright (C) 1988-1989, 1992-1995, 1998, 2001-2002, 2004, 2006, 2009-2013,
-   2015-2025 Free Software Foundation, Inc.
+   2015-2026 Free Software Foundation, Inc.

   This file is part of GNU DIFF.

@ -1012,7 +1012,7 @@ find_and_hash_each_line (struct file_data *current)
 	  linbuf += linbuf_base;
 	  linbuf = xpalloc (linbuf, &n, 1, -1, sizeof *linbuf);
 	  linbuf -= linbuf_base;
-	  alloc_lines = n - linbuf_base;
+	  alloc_lines = linbuf_base + n;
        }
      linbuf[line] = p;

--- a/src/normal.c
+++ b/src/normal.c
@ -1,6 +1,6 @@
 /* Normal-format output routines for GNU DIFF.

-   Copyright (C) 1988-1989, 1993, 1995, 1998, 2001, 2006, 2009-2013, 2015-2025
+   Copyright (C) 1988-1989, 1993, 1995, 1998, 2001, 2006, 2009-2013, 2015-2026
   Free Software Foundation, Inc.

   This file is part of GNU DIFF.
--- a/src/sdiff.c
+++ b/src/sdiff.c
@ -1,7 +1,7 @@
 /* GNU sdiff - side-by-side merge of file differences

   Copyright (C) 1992-1996, 1998, 2001-2002, 2004, 2006-2007, 2009-2013,
-   2015-2025 Free Software Foundation, Inc.
+   2015-2026 Free Software Foundation, Inc.

   This file is part of GNU DIFF.

@ -100,7 +100,9 @@ enum
 typedef void (*sighandler) (int);
 static void signal_handler (int, sighandler);

-#if HAVE_SIGACTION
+/* Use SA_NOCLDSTOP as a proxy for whether the sigaction machinery is
+   present.  */
+#ifdef SA_NOCLDSTOP
 /* Prefer 'sigaction' if available, since 'signal' can lose signals.  */
 static struct sigaction initial_action[NUM_SIGS];
 static sighandler
@ -714,21 +716,21 @@ static bool sigs_trapped;
 static void
 catchsig (int s)
 {
-#if ! HAVE_SIGACTION
+#ifndef SA_NOCLDSTOP
  signal (s, SIG_IGN);
 #endif
  if (! (s == SIGINT && ignore_SIGINT))
    signal_received = s;
 }

-#if HAVE_SIGACTION
+#ifdef SA_NOCLDSTOP
 static struct sigaction catchaction;
 #endif

 static void
 signal_handler (int sig, sighandler handler)
 {
-#if HAVE_SIGACTION
+#ifdef SA_NOCLDSTOP
  catchaction.sa_handler = handler;
  sigaction (sig, &catchaction, 0);
 #else
@ -739,7 +741,7 @@ signal_handler (int sig, sighandler handler)
 static void
 trapsigs (void)
 {
-#if HAVE_SIGACTION
+#ifdef SA_NOCLDSTOP
  catchaction.sa_flags = SA_RESTART;
  sigemptyset (&catchaction.sa_mask);
  for (int i = 0;  i < NUM_SIGS;  i++)
@ -748,7 +750,7 @@ trapsigs (void)

  for (int i = 0;  i < NUM_SIGS;  i++)
    {
-#if HAVE_SIGACTION
+#ifdef SA_NOCLDSTOP
      sigaction (sigs[i], nullptr, &initial_action[i]);
 #else
      initial_action[i] = signal (sigs[i], SIG_IGN);
@ -773,7 +775,7 @@ untrapsig (int s)
    for (int i = 0;  i < NUM_SIGS;  i++)
      if ((! s || sigs[i] == s)  &&  initial_handler (i) != SIG_IGN)
        {
-#if HAVE_SIGACTION
+#ifdef SA_NOCLDSTOP
          sigaction (sigs[i], &initial_action[i], nullptr);
 #else
          signal (sigs[i], initial_action[i]);
@ -802,7 +804,7 @@ checksigs (void)
 static void
 give_help (void)
 {
-  fprintf (stderr, "%s", _("\
+  fputs (_("\
 ed:\tEdit then use both versions, each decorated with a header.\n\
 eb:\tEdit then use both versions.\n\
 el or e1:\tEdit then use the left version.\n\
@ -813,20 +815,15 @@ r or 2:\tUse the right version.\n\
 s:\tSilently include common lines.\n\
 v:\tVerbosely include common lines.\n\
 q:\tQuit.\n\
-"));
+"), stderr);
 }

 static int
 skip_white (void)
 {
  int c;
-  for (;;)
-    {
-      c = getchar ();
-      if (! c_isspace (c) || c == '\n')
-        break;
-      checksigs ();
-    }
+  while ((c = getchar ()) != '\n' && c_isspace (c))
+    checksigs ();
  if (ferror (stdin))
    perror_fatal (_("read failed"));
  return c;
@ -856,8 +853,7 @@ edit (struct line_filter *left, char const *lname, lin lline, lin llen,
 {
  for (;;)
    {
-      int cmd0;
-      int cmd1;
+      int cmd;
      bool gotcmd = false;

      while (! gotcmd)
@ -866,48 +862,41 @@ edit (struct line_filter *left, char const *lname, lin lline, lin llen,
            perror_fatal (_("write failed"));
          ck_fflush (stdout);

-          cmd0 = skip_white ();
-          switch (cmd0)
+	  cmd = skip_white ();
+          switch (cmd)
            {
-            case '1': case '2': case 'l': case 'r':
-            case 's': case 'v': case 'q':
-              if (skip_white () != '\n')
-                {
-                  give_help ();
-                  flush_line ();
-                  continue;
-                }
-              gotcmd = true;
-              break;
-
-            case 'e':
-              cmd1 = skip_white ();
+	    case 'e':;
+	      int cmd1 = skip_white ();
              switch (cmd1)
                {
-                case '1': case '2': case 'b': case 'd': case 'l': case 'r':
-                  if (skip_white () != '\n')
-                    {
-                      give_help ();
-                      flush_line ();
-                      continue;
-                    }
-                  gotcmd = true;
-                  break;
                case '\n':
                  gotcmd = true;
-                  break;
+		  continue;
                default:
                  give_help ();
                  flush_line ();
-                  continue;
+		  continue;
+		case '1': case '2': case 'b': case 'd': case 'l': case 'r':
+		  cmd |= cmd1 << UCHAR_WIDTH;
+		  break;
                }
+	      FALLTHROUGH;
+	    case '1': case '2': case 'l': case 'r':
+	    case 's': case 'v': case 'q':
+	      if (skip_white () == '\n')
+		gotcmd = true;
+	      else
+		{
+		  give_help ();
+		  flush_line ();
+		}
              break;

            case EOF:
              if (feof (stdin))
                {
                  gotcmd = true;
-                  cmd0 = 'q';
+                  cmd = 'q';
                  break;
                }
              FALLTHROUGH;
@ -916,11 +905,11 @@ edit (struct line_filter *left, char const *lname, lin lline, lin llen,
              FALLTHROUGH;
            case '\n':
              give_help ();
-              continue;
+	      break;
            }
        }

-      switch (cmd0)
+      switch (cmd & UCHAR_MAX)
        {
        case '1': case 'l':
          lf_copy (left, llen, outfile);
@ -953,6 +942,7 @@ edit (struct line_filter *left, char const *lname, lin lline, lin llen,
          if (! tmp)
 	    perror_fatal (squote (0, tmpname));

+	  int cmd1 = cmd >> UCHAR_WIDTH;
          switch (cmd1)
            {
            case 'd':
--- a/src/side.c
+++ b/src/side.c
@ -1,6 +1,6 @@
 /* sdiff-format output routines for GNU DIFF.

-   Copyright (C) 1991-1993, 1998, 2001-2002, 2004, 2009-2013, 2015-2025 Free
+   Copyright (C) 1991-1993, 1998, 2001-2002, 2004, 2009-2013, 2015-2026 Free
   Software Foundation, Inc.

   This file is part of GNU DIFF.
--- a/src/syncsig.c
+++ b/src/syncsig.c
@ -0,0 +1,350 @@
+/* Synchronous signal handling
+
+   Copyright 2025-2026 Free Software Foundation, Inc.
+
+   This file is part of GNU DIFF.
+
+   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 "syncsig.h"
+
+#include "minmax.h"
+
+#include <signal.h>
+#include <stdcountof.h>
+
+/* Use SA_NOCLDSTOP as a proxy for whether the sigaction machinery is
+   present.  */
+#ifndef SA_NOCLDSTOP
+# define SA_NOCLDSTOP 0
+# define sigprocmask(how, set, oset) 0
+# if ! HAVE_SIGINTERRUPT
+#  define siginterrupt(sig, flag) 0
+# endif
+#endif
+
+#ifndef SA_RESTART
+# define SA_RESTART 0
+#endif
+#ifndef SIGSTOP
+# define SIGSTOP 0
+#endif
+
+/* The set of signals that are caught.  */
+static sigset_t caught_signals;
+
+/* The signals we can catch.
+   This includes all catchable GNU/Linux or POSIX signals that by
+   default are ignored, or that stop or terminate the process.
+   It also includes SIGQUIT since that can come from the terminal.
+   It excludes other signals that normally come from program failure.
+   If you modify this table, also modify signal_count's initializer.  */
+static int const catchable[] =
+  {
+    /* SIGABRT is normally from program failure.  */
+    SIGALRM,
+    /* SIGBUS is normally from program failure.  */
+#ifdef SIGCHLD
+    SIGCHLD,
+#else
+# define SIGCHLD 0
+#endif
+    /* SIGCLD (older platforms) is an alias for SIGCHLD.  */
+#ifdef SIGCONT
+    SIGCONT,
+#else
+# define SIGCONT 0
+#endif
+    /* SIGEMT is normally from program failure.  */
+    /* SIGFPE is normally from program failure.  */
+    SIGHUP,
+    /* SIGILL is normally from program failure.  */
+    /* SIGINFO is an alias for SIGPWR on Linux.  */
+    SIGINT,
+    /* SIGIO is an alias for SIGPOLL.  */
+    /* SIGKILL can't be caught.  */
+#ifdef SIGLOST
+    SIGLOST,
+#else
+# define SIGLOST 0
+#endif
+    SIGPIPE,
+#ifdef SIGPOLL /* Removed from POSIX.1-2024; still in Linux.  */
+    SIGPOLL,
+#else
+# define SIGPOLL 0
+#endif
+#ifdef SIGPROF /* Removed from POSIX.1-2024; still in Linux.  */
+    SIGPROF,
+#else
+# define SIGPROF 0
+#endif
+#ifdef SIGPWR
+    SIGPWR,
+#else
+# define SIGPWR 0
+#endif
+    SIGQUIT,
+    /* SIGSEGV is normally from program failure.  */
+    /* Linux SIGSTKFLT is unused.  */
+    /* SIGSTOP can't be caught.  */
+    /* SIGSYS is normally from program failure.  */
+    SIGTERM,
+    /* SIGTRAP is normally from program failure.  */
+#ifdef SIGTSTP
+    SIGTSTP,
+#else
+# define SIGTSTP 0
+#endif
+#ifdef SIGTTIN
+    SIGTTIN,
+#else
+# define SIGTTIN 0
+#endif
+#ifdef SIGTTOU
+    SIGTTOU,
+#else
+# define SIGTTOU 0
+#endif
+#ifdef SIGURG
+    SIGURG,
+#else
+# define SIGURG 0
+#endif
+#ifdef SIGUSR1
+    SIGUSR1,
+#else
+# define SIGUSR1 0
+#endif
+#ifdef SIGUSR2
+    SIGUSR2,
+#else
+# define SIGUSR2 0
+#endif
+#ifdef SIGVTALRM
+    SIGVTALRM,
+#else
+# define SIGVTALRM 0
+#endif
+#ifdef SIGWINCH
+    SIGWINCH,
+#else
+# define SIGWINCH 0
+#endif
+#ifdef SIGXCPU
+    SIGXCPU,
+#else
+# define SIGXCPU 0
+#endif
+#ifdef SIGXFSZ
+    SIGXFSZ,
+#else
+# define SIGXFSZ 0
+#endif
+  };
+
+/* Number of pending signals received, for each signal type.  */
+static sig_atomic_t volatile signal_count[] =
+  {
+    /* Explicitly initialize, so that the table is large enough.  */
+    [SIGALRM] = 0,
+    [SIGCHLD] = 0,
+    [SIGCONT] = 0,
+    [SIGHUP] = 0,
+    [SIGINT] = 0,
+    [SIGLOST] = 0,
+    [SIGPIPE] = 0,
+    [SIGPOLL] = 0,
+    [SIGPROF] = 0,
+    [SIGPWR] = 0,
+    [SIGQUIT] = 0,
+    [SIGTERM] = 0,
+    [SIGTSTP] = 0,
+    [SIGTTIN] = 0,
+    [SIGTTOU] = 0,
+    [SIGURG] = 0,
+    [SIGUSR1] = 0,
+    [SIGUSR2] = 0,
+    [SIGVTALRM] = 0,
+    [SIGWINCH] = 0,
+    [SIGXCPU] = 0,
+    [SIGXFSZ] = 0,
+  };
+
+/* This acts as bool though its type is sig_atomic_t.
+   If true, signal_count might contain nonzero entries.
+   If false, signal_count is all zero.
+   This is to speed up syncsig_poll when it returns 0.  */
+static sig_atomic_t volatile possible_signal_count;
+
+/* Actions before syncsig_install was called.  */
+#if SA_NOCLDSTOP
+static struct sigaction oldact[countof (signal_count)];
+#else
+static void (*oldact[countof (signal_count)]) (int);
+#endif
+
+/* Record an asynchronous signal.  This function is async-signal-safe.  */
+static void
+sighandler (int sig)
+{
+#if !SA_NOCLDSTOP
+  /* An unavoidable race here: the default action might mistakenly
+     be taken before 'signal' is called.  */
+  signal (sig, sighandler);
+#endif
+
+  possible_signal_count = true;
+  signal_count[sig]++;
+}
+
+void
+syncsig_install (int flags)
+{
+  for (int i = 0; i < countof (catchable); i++)
+    signal_count[catchable[i]] = 0;
+  possible_signal_count = false;
+
+  sigemptyset (&caught_signals);
+
+  for (int i = 0; i < countof (catchable); i++)
+    {
+      int sig = catchable[i];
+
+      if (((sig == SIGTSTP) & !(flags & SYNCSIG_TSTP))
+	  | ((sig == SIGTTIN) & !(flags & SYNCSIG_TTIN))
+	  | ((sig == SIGTTOU) & !(flags & SYNCSIG_TTOU)))
+	continue;
+
+#if SA_NOCLDSTOP
+      sigaction (sig, nullptr, &oldact[sig]);
+      bool catching_sig = oldact[sig].sa_handler != SIG_IGN;
+#else
+      oldact[i] = signal (sig, SIG_IGN);
+      bool catching_sig = oldact[i] != SIG_IGN;
+      if (catching_sig)
+	{
+	  /* An unavoidable race here: SIG might be mistakenly ignored
+	     before 'signal' is called.  */
+	  signal (sig, sighandler);
+	  siginterrupt (sig, 0);
+	}
+#endif
+      if (catching_sig)
+	sigaddset (&caught_signals, sig);
+    }
+
+#if SA_NOCLDSTOP
+  struct sigaction act;
+  act.sa_handler = sighandler;
+  act.sa_mask = caught_signals;
+  act.sa_flags = SA_RESTART;
+
+  for (int i = 0; i < countof (catchable); i++)
+    {
+      int sig = catchable[i];
+      if (sigismember (&caught_signals, sig))
+	sigaction (sig, &act, nullptr);
+    }
+#endif
+}
+
+void
+syncsig_uninstall (void)
+{
+  for (int i = 0; i < countof (catchable); i++)
+    {
+      int sig = catchable[i];
+      if (sigismember (&caught_signals, sig))
+	{
+#if SA_NOCLDSTOP
+	  sigaction (sig, &oldact[sig], nullptr);
+#else
+	  signal (sig, oldact[sig]);
+#endif
+	}
+    }
+}
+
+int
+syncsig_poll (void)
+{
+  int sig = 0;
+
+  if (possible_signal_count)
+    {
+      /* This module uses static rather than thread-local storage,
+	 so it is useful only in single-threaded programs,
+	 and it uses sigprocmask rather than pthread_sigmask.  */
+      sigset_t oldset;
+      sigprocmask (SIG_BLOCK, &caught_signals, &oldset);
+
+      for (int i = 0; ; i++)
+	{
+	  if (i == countof (catchable))
+	    {
+	      possible_signal_count = false;
+	      break;
+	    }
+	  int s = catchable[i];
+	  int c = signal_count[s];
+	  if (c)
+	    {
+	      signal_count[s] = c - 1;
+	      sig = s;
+	      break;
+	    }
+	}
+
+      sigprocmask (SIG_SETMASK, &oldset, nullptr);
+    }
+
+  return sig;
+}
+
+void
+syncsig_deliver (int sig)
+{
+#if SA_NOCLDSTOP
+  struct sigaction act;
+#else
+  void (*act) (int);
+#endif
+
+  if (sig == SIGTSTP)
+    sig = SIGSTOP;
+  else
+    {
+#if SA_NOCLDSTOP
+      sigaction (sig, &oldact[sig], &act);
+#else
+      act = signal (sig, oldact[sig]);
+#endif
+
+    }
+
+  raise (sig);
+
+  if (sig != SIGSTOP)
+    {
+      /* The program did not exit due to the raised signal, so continue.  */
+#if SA_NOCLDSTOP
+      sigaction (sig, &act, nullptr);
+#else
+      signal (sig, act);
+#endif
+    }
+}
--- a/src/syncsig.h
+++ b/src/syncsig.h
@ -0,0 +1,60 @@
+/* Synchronous signal handling
+
+   Copyright 2025-2026 Free Software Foundation, Inc.
+
+   This file is part of GNU DIFF.
+
+   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 Paul Eggert.  */
+
+/* Flags for syncsig_install.  */
+enum
+  {
+    /* Also catch SIGTSTP, SIGTTIN, SIGTTOU, which by default stop the process.
+       These flags have no effect on platforms lacking these signals.  */
+    SYNCSIG_TSTP = (1 << 0),
+    SYNCSIG_TTIN = (1 << 1),
+    SYNCSIG_TTOU = (1 << 2),
+  };
+
+/* Set up asynchronous signal handling according to FLAGS.
+   syncsig_install fails only on unusual platforms where
+   valid calls to functions like sigaction can fail;
+   if it fails, signal handling is in a weird state
+   and neither syncsig_process nor syncsig_uninstall should be called.  */
+extern void syncsig_install (int flags);
+
+/* Return a signal number if a signal has arrived, zero otherwise.
+   After syncsig_install, there should not be an unbounded amount of
+   time between calls to this function, and its result should be dealt
+   with promptly.  */
+extern int syncsig_poll (void);
+
+/* Do the action for SIG that would have been done
+   had syncsig_install not been called.
+   SIG should have recently been returned by syncsig_poll.
+
+   For example, if SIG is SIGTSTP stop the process and return after
+   SIGCONT is delivered.  Another example: kill the process if SIG is
+   SIGINT and SIGINT handling is the default.
+
+   This function should be called only after syncsig_install.  */
+extern void syncsig_deliver (int sig);
+
+/* Stop doing asynchronous signal handling, undoing syncsig_install.
+   This function should be called only after syncsig_install.
+   To deal with signals arriving just before calling this function,
+   call syncsig_poll afterwards.  */
+extern void syncsig_uninstall (void);
--- a/src/system.c
+++ b/src/system.c
@ -1,7 +1,7 @@
 /* System dependent declarations.

   Copyright (C) 1988-1989, 1992-1995, 1998, 2001-2002, 2004, 2006, 2009-2013,
-   2015-2025 Free Software Foundation, Inc.
+   2015-2026 Free Software Foundation, Inc.

   This file is part of GNU DIFF.

--- a/src/system.h
+++ b/src/system.h
@ -1,7 +1,7 @@
 /* System dependent declarations.

   Copyright (C) 1988-1989, 1992-1995, 1998, 2001-2002, 2004, 2006, 2009-2013,
-   2015-2025 Free Software Foundation, Inc.
+   2015-2026 Free Software Foundation, Inc.

   This file is part of GNU DIFF.

--- a/src/util.c
+++ b/src/util.c
@ -1,7 +1,7 @@
 /* Support routines for GNU DIFF.

   Copyright (C) 1988-1989, 1992-1995, 1998, 2001-2002, 2004, 2006, 2009-2013,
-   2015-2025 Free Software Foundation, Inc.
+   2015-2026 Free Software Foundation, Inc.

   This file is part of GNU DIFF.

@ -27,31 +27,11 @@
 #include <flexmember.h>
 #include <mcel.h>
 #include <quotearg.h>
+#include <syncsig.h>
 #include <system-quote.h>
 #include <xalloc.h>

 #include <stdarg.h>
-#include <signal.h>
-
-/* Use SA_NOCLDSTOP as a proxy for whether the sigaction machinery is
-   present.  */
-#ifndef SA_NOCLDSTOP
-# define SA_NOCLDSTOP 0
-# define sigprocmask(How, Set, Oset) 0
-# if ! HAVE_SIGINTERRUPT
-#  define siginterrupt(sig, flag) 0
-# endif
-#endif
-
-#ifndef SA_RESTART
-# define SA_RESTART 0
-#endif
-#ifndef SIGSTOP
-# define SIGSTOP 0
-#endif
-#ifndef SIGTSTP
-# define SIGTSTP 0
-#endif

 char const pr_program[] = PR_PROGRAM;

@ -184,78 +164,9 @@ print_message_queue (void)
      m = next;
    }
 }
-
+
 /* Signal handling, needed for restoring default colors.  */

-static void
-xsigaddset (sigset_t *set, int sig)
-{
-  if (sigaddset (set, sig) != 0)
-    pfatal_with_name ("sigaddset");
-}
-
-static bool
-xsigismember (sigset_t const *set, int sig)
-{
-  int mem = sigismember (set, sig);
-  if (mem < 0)
-    pfatal_with_name ("sigismember");
-  assume (mem <= 1);
-  return mem;
-}
-
-typedef void (*signal_handler) (int);
-static signal_handler
-xsignal (int sig, signal_handler func)
-{
-  signal_handler h = signal (sig, func);
-  if (h == SIG_ERR)
-    pfatal_with_name ("signal");
-  return h;
-}
-
-static void
-xsigprocmask (int how, sigset_t const *restrict set, sigset_t *restrict oset)
-{
-  if (sigprocmask (how, set, oset) != 0)
-    pfatal_with_name ("sigprocmask");
-}
-
-/* If true, some signals are caught.  This is separate from
-   'caught_signals' because POSIX doesn't require an all-zero sigset_t
-   to be valid.  */
-static bool some_signals_caught;
-
-/* The set of signals that are caught.  */
-static sigset_t caught_signals;
-
-/* If nonzero, the value of the pending fatal signal.  */
-static sig_atomic_t volatile interrupt_signal;
-
-/* A count of the number of pending stop signals that have been received.  */
-static sig_atomic_t volatile stop_signal_count;
-
-/* An ordinary signal was received; arrange for the program to exit.  */
-
-static void
-sighandler (int sig)
-{
-  if (! SA_NOCLDSTOP)
-    signal (sig, SIG_IGN);
-  if (! interrupt_signal)
-    interrupt_signal = sig;
-}
-
-/* A SIGTSTP was received; arrange for the program to suspend itself.  */
-
-static void
-stophandler (int sig)
-{
-  if (! SA_NOCLDSTOP)
-    signal (sig, stophandler);
-  if (! interrupt_signal)
-    stop_signal_count++;
-}
 /* Process any pending signals.  If signals are caught, this function
   should be called periodically.  Ideally there should never be an
   unbounded amount of time when signals are not being processed.
@ -265,131 +176,18 @@ stophandler (int sig)
 static void
 process_signals (void)
 {
-  while (interrupt_signal | stop_signal_count)
+  for (int sig; (sig = syncsig_poll ()); )
    {
      set_color_context (RESET_CONTEXT);
      fflush (stdout);
-
-      sigset_t oldset;
-      xsigprocmask (SIG_BLOCK, &caught_signals, &oldset);
-
-      /* Reload stop_signal_count and (if needed) interrupt_signal, in
-	 case a new signal was handled before sigprocmask took effect.  */
-      int stops = stop_signal_count, sig;
-
-      /* SIGTSTP is special, since the application can receive that signal
-         more than once.  In this case, don't set the signal handler to the
-         default.  Instead, just raise the uncatchable SIGSTOP.  */
-      if (stops)
-        {
-          stop_signal_count = stops - 1;
-          sig = SIGSTOP;
-        }
-      else
-	{
-	  sig = interrupt_signal;
-	  xsignal (sig, SIG_DFL);
-	}
-
-      /* Exit or suspend the program.  */
-      if (raise (sig) != 0)
-	pfatal_with_name ("raise");
-      xsigprocmask (SIG_SETMASK, &oldset, nullptr);
-
-      /* If execution reaches here, then the program has been
-         continued (after being suspended).  */
+      syncsig_deliver (sig);
    }
 }

-/* The signals that can be caught, the number of such signals,
-   and which of them are actually caught.  */
-static int const sig[] =
-  {
-#if SIGTSTP
-    /* This one is handled specially; see is_tstp_index.  */
-    SIGTSTP,
-#endif
-
-    /* The usual suspects.  */
-#ifdef SIGALRM
-    SIGALRM,
-#endif
-#ifdef SIGHUP
-    SIGHUP,
-#endif
-    SIGINT,
-#ifdef SIGPIPE
-    SIGPIPE,
-#endif
-#ifdef SIGQUIT
-    SIGQUIT,
-#endif
-    SIGTERM,
-#ifdef SIGPOLL
-    SIGPOLL,
-#endif
-#ifdef SIGPROF
-    SIGPROF,
-#endif
-#ifdef SIGVTALRM
-    SIGVTALRM,
-#endif
-#ifdef SIGXCPU
-    SIGXCPU,
-#endif
-#ifdef SIGXFSZ
-    SIGXFSZ,
-#endif
-  };
-enum { nsigs = sizeof (sig) / sizeof *(sig) };
-
-/* True if sig[j] == SIGTSTP.  */
-static bool
-is_tstp_index (int j)
-{
-  return SIGTSTP && j == 0;
-}
-
 static void
 install_signal_handlers (void)
 {
-  if (sigemptyset (&caught_signals) != 0)
-    pfatal_with_name ("sigemptyset");
-
-#if SA_NOCLDSTOP
-  for (int j = 0; j < nsigs; j++)
-    {
-      struct sigaction actj;
-      if (sigaction (sig[j], nullptr, &actj) == 0 && actj.sa_handler != SIG_IGN)
-	xsigaddset (&caught_signals, sig[j]);
-    }
-
-  struct sigaction act;
-  act.sa_mask = caught_signals;
-  act.sa_flags = SA_RESTART;
-
-  for (int j = 0; j < nsigs; j++)
-    if (xsigismember (&caught_signals, sig[j]))
-      {
-	act.sa_handler = is_tstp_index (j) ? stophandler : sighandler;
-	if (sigaction (sig[j], &act, nullptr) != 0)
-	  pfatal_with_name ("sigaction");
-	some_signals_caught = true;
-      }
-#else
-  for (int j = 0; j < nsigs; j++)
-    {
-      signal_handler h = signal (sig[j], SIG_IGN);
-      if (h != SIG_IGN && h != SIG_ERR)
-	{
-	  xsigaddset (&caught_signals, sig[j]);
-	  xsignal (sig[j], is_tstp_index (j) ? stophandler : sighandler);
-	  some_signals_caught = true;
-	  if (siginterrupt (sig[j], 0) != 0)
-	    pfatal_with_name ("siginterrupt");
-	}
-    }
-#endif
+  syncsig_install (SYNCSIG_TSTP);
 }

 /* Clean up signal handlers just before exiting the program.  Do this
@ -398,14 +196,11 @@ install_signal_handlers (void)
 void
 cleanup_signal_handlers (void)
 {
-  if (some_signals_caught)
-    {
-      for (int j = 0; j < nsigs; j++)
-	if (xsigismember (&caught_signals, sig[j]))
-	  xsignal (sig[j], SIG_DFL);
-      process_signals ();
-    }
+  syncsig_uninstall ();
+  process_signals ();
 }
+
+/* Color handling.  */

 static char const *current_name[2];
 static bool currently_recursive;
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@ -9,6 +9,7 @@ TESTS = \
  cmp \
  colliding-file-names \
  diff3 \
+  empty-file \
  excess-slash \
  expand-tabs \
  help-version	\
@ -24,6 +25,7 @@ TESTS = \
  no-dereference \
  no-newline-at-eof \
  side-by-side \
+  side-by-side-seq \
  starting-file \
  stdin \
  strcoll-0-names \
--- a/tests/cmp
+++ b/tests/cmp
@ -1,7 +1,7 @@
 #!/bin/sh
 # Test 'cmp'.

-# Copyright 2017-2025 Free Software Foundation, Inc.
+# Copyright 2017-2026 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
@ -247,7 +247,7 @@ cmp -i 1000 -n $big j1 j2 || fail=1

 rm -f a b
 if timeout 0.1 true && truncate -s 14T a && truncate -s 15T b; then
-  returns_ 1 timeout 0.1 cmp a b >/dev/null || fail=1
+  returns_ 1 timeout 0.4 cmp a b >/dev/null || fail=1
 fi
 rm -f a b

--- a/tests/diff3
+++ b/tests/diff3
@ -3,18 +3,6 @@

 . "${srcdir=.}/init.sh"; path_prepend_ ../src

-# Some systems lack seq.
-# A limited replacement for seq: handle 1 or 2 args; increment must be 1
-seq()
-{
-  case $# in
-    1) start=1  final=$1;;
-    2) start=$1 final=$2;;
-    *) echo you lose 1>&2; exit 1;;
-  esac
-  awk 'BEGIN{for(i='$start';i<='$final';i++) print i}' < /dev/null
-}
-
 echo a > a || framework_failure_
 echo b > b || framework_failure_
 echo c > c || framework_failure_
--- a/tests/empty-file
+++ b/tests/empty-file
@ -0,0 +1,23 @@
+#!/bin/sh
+# Test empty files
+
+. "${srcdir=.}/init.sh"; path_prepend_ ../src
+
+fail=0
+mkdir a b
+touch a/test
+echo 'content' > b/test
+
+returns_ 1 diff -Naur a b >out || fail=1
+cat <<EOF > expected || framework_failure_
+diff -Naur a/test b/test
+--- a/test
+++ b/test
+@@ -0,0 +1 @@
+content
+EOF
+# Remove date and time.
+sed -e 's/^\([-+*][-+*][-+*] [^	]*\)	.*/\1/' out > k; mv k out
+compare expected out || fail=1
+
+Exit $fail
--- a/tests/envvar-check
+++ b/tests/envvar-check
@ -1,7 +1,7 @@
 # -*- sh -*-
 # Check environment variables for sane values while testing.

-# Copyright (C) 2000-2025 Free Software Foundation, Inc.
+# Copyright (C) 2000-2026 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
--- a/tests/help-version
+++ b/tests/help-version
@ -2,7 +2,7 @@
 # Make sure all these programs work properly
 # when invoked with --help or --version.

-# Copyright (C) 2000-2013, 2015-2025 Free Software Foundation, Inc.
+# Copyright (C) 2000-2013, 2015-2026 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
--- a/tests/init.cfg
+++ b/tests/init.cfg
@ -1,6 +1,6 @@
 # This file is sourced by init.sh, *before* its initialization.

-# Copyright (C) 2010-2025 Free Software Foundation, Inc.
+# Copyright (C) 2010-2026 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
@ -120,4 +120,16 @@ require_utf8_locale_()
  test $found_working_tr = 1 || skip_ "failed to find a working tr program"
 }

+# Some systems lack seq.
+# A limited replacement for seq: handle 1 or 2 args; increment must be 1
+seq()
+{
+  case $# in
+    1) start=1  final=$1;;
+    2) start=$1 final=$2;;
+    *) echo you lose 1>&2; exit 1;;
+  esac
+  awk 'BEGIN{for(i='$start';i<='$final';i++) print i}' < /dev/null
+}
+
 sanitize_path_
--- a/tests/side-by-side-seq
+++ b/tests/side-by-side-seq
@ -0,0 +1,26 @@
+#!/bin/sh
+# Test side-by-side output on sequences.
+
+. "${srcdir=.}/init.sh"; path_prepend_ ../src
+
+fail=0
+
+seq 1 100 >in1 || framework_failure_
+(seq 1 49 && seq 51 100) >in2 || framework_failure_
+awk '
+  BEGIN {
+    for (i = 1; i <= 100; i++) {
+      if (i == 50) {
+        print "50   <"
+      } else {
+        printf "%d\t%d\n", i, i
+      }
+    }
+  }
+' </dev/null >exp || framework_failure_
+
+returns_ 1 diff -yW 11 in1 in2 >out 2>err || fail=1
+compare exp out || fail=1
+compare /dev/null err || fail=1
+
+Exit $fail
Author	SHA1	Message	Date
Jim Meyering	bbc1bdb771	maint: update copyright dates	2026-01-02 16:52:26 -08:00
Jim Meyering	301eca636b	build: update gnulib to latest, and update bootstrap	2026-01-02 16:51:54 -08:00
Paul Eggert	33ce4260b8	diff: tweak -q, -s doc Problem reported by Dan Jacobsen (bug#79959). * src/diff.c (option_help_msgid): Tweak.	2025-12-07 09:41:44 -08:00
Paul Eggert	6ad4a619d4	diff: tweak signal initialization * src/syncsig.c (syncsig_install): No need to initialize all of signal_count; just the catchable signals.	2025-12-03 09:40:35 -08:00
Paul Eggert	916b50fe96	diff: no need to avoid localcharset This fixes builds on macOS 12–14. Problem reported by Bruno Haible (Bug#79887). * bootstrap.conf (avoided_gnulib_modules): Remove localcharset.	2025-12-03 09:40:35 -08:00
Paul Eggert	a1432a6216	build: update gnulib submodule to latest * src/context.c (print_contenxt_label): Adjust to recent Gnulib changes to nstrftime API.	2025-11-02 13:09:16 -08:00
Paul Eggert	a709a0a2bd	diff: simplify sigaction configuration * configure.ac: Remove checks for sigaction, sigprocmask, sigblock. The sigprocmask and sigblock checks were not being used anyway. * src/sdiff.c: Use (defined SA_NOCLDSTOP) instead of HAVE_SIGACTION. This is what other modules do.	2025-11-02 13:09:16 -08:00
Paul Eggert	b4524ba9a6	diff: refactor and improve signal handling This is so we can improve sdiff signal handling. * bootstrap.conf: Add stdcountof-h. * src/Makefile.am (diff_SOURCES): Add syncsig.c. (noinst_HEADERS): Add syncsig.h. * src/diff.c, src/util.c: Include syncsig.h. * src/util.c: Move signal-related stuff from here ... * src/syncsig.c: ... to here. (syncsig_install, syncsig_cleanup): Rename from install_signal_handlers, cleanup_signal_handlers. All uses changed. Handle some more signals. Add an option to not handle stop-related signals. (syncsig_poll, syncsig_deliver): New functions, which are like the old process_signals but in two pieces not one. All uses changed. (syncsig_install): New args FUN and ARG. Return int on failure. All callers changed. * src/syncsig.h: New file.	2025-11-02 13:09:16 -08:00
Paul Eggert	6b9c726076	maint: use our textdomain for Gnulib Support diffutils’ traditional way of getting translations, by telling Gnulib to use diffutils’ message catalog. * configure.ac (GNULIB_TEXT_DOMAIN): New macro. * src/cmp.c, src/diff.c, src/diff3.c, src/sdiff.c (main): Don’t call bindtextdomain ("gnulib", GNULIB_LOCALEDIR) as the existing bindtextdomain (PACKAGE, LOCALEDIR) call suffices.	2025-09-09 10:23:01 -07:00
Paul Eggert	3ccfcd8cd7	build: update gnulib submodule to latest	2025-09-09 10:23:01 -07:00
Paul Eggert	096a3b29b5	maint: remove po/en.po * po/en.po: Remove. It wasn’t being used, and we’re now doing its intent in a less-hassly way.	2025-09-09 10:23:01 -07:00
Paul Eggert	dc6dc9147f	cmp: improve LC_MESSAGES test * src/cmp.c (hard_locale_LC_MESSAGES): Use setlocale, not gettext, to decide whether the messages might not be those of the C or POSIX locale. This is a more reliable way to test whether the locale is something like en_US.utf8, a locale that does not have a translation catalog but is not the C locale.	2025-09-09 10:23:01 -07:00
Paul Eggert	cf5648869a	maint: use need-formatstring-macros * configure.ac: Pass need-formatstring-macros, not merely need-ngettext, to AM_GNU_GETTEXT. This is mostly for show, as diffutils has used format string macros for years and since nobody uses ancient gettext any more nobody has noticed a problem.	2025-09-09 10:23:01 -07:00
Paul Eggert	e124541148	maint: reduce Gnulib module usage Recentish changes to Gnulib have pulled in more dependencies on multithreading, locking, and whatnot. Revamp to remove these unwanted dependencies. * bootstrap.conf: Also avoid hard-locale, localcharset, localename-unsafe, localename-unsafe-limited. Stop avoiding localename. (avoided_gnulib_tests): New var. Avoid these tests too. (gnulib-modules): Remove hard-locale, nstrftime. Add nstrftime-limited. * configure.ac (gl_cv_func_mbrtowc_C_locale_sans_EILSEQ) (gl_cv_func_mbrtoc32_C_locale_sans_EILSEQ): New vars, so that we do not worry about multibyte C locales. (gl_THREADLIB_DEFAULT_NO): New macro. Not sure how much it helps, but it can’t hurt. (SUPPORT_NON_GREG_CALENDARS_IN_STRFTIME): New macro. * src/cmp.c: Do not include hard-locale.h. (hard_locale_LC_MESSAGES): Assume that LC_MESSAGES is hard if and only if "(C)" gets translated. This drags in fewer dependencies than calling hard_locale. * src/diff.c: Include strftime.h instead of hard-locale.h. (hard_locale_LC_TIME): New function, that uses nstrftime to infer whether the time locale is hard. (main): Use it instead of hard_locale. maint: default Gnulib to no multithreading * configure.ac: Define gl_THREADLIB_DEFAULT_NO so that Gnulib defaults to no multithreading.	2025-09-05 14:47:08 -07:00
Paul Eggert	42083759b6	build: update gnulib submodule to latest	2025-09-05 14:47:08 -07:00
Paul Eggert	c08704493d	sdiff: simplify give_help slightly * src/sdiff.c (give_help): Simplify by using fputs instead of fprintf.	2025-09-05 14:47:08 -07:00
Paul Eggert	f3f02235de	diff: simplify usage slightly * src/diff.c (usage): Simplify by omitting a need to call putchar.	2025-09-05 14:47:08 -07:00
Bruno Haible	0cba18b965	build: Update after gnulib changed * gnulib-tests/Makefile.am: Initialize AM_CFLAGS.	2025-09-05 14:47:08 -07:00
Paul Eggert	2591992037	diff: reduce nstrftime dependency * configure.ac (REQUIRE_GNUISH_STRFTIME_AM_PM): Define to 0, since we don’t use AM or PM indicators.	2025-04-27 23:42:49 -07:00
Paul Eggert	c191460adf	sdiff: refactor simplification * src/sdiff.c (skip_white): Simplify a loop. (edit): Redo nested switches to avoid duplicate code.	2025-04-27 23:42:49 -07:00
Paul Eggert	686357a40c	sdiff: port back to C17- * src/sdiff.c (edit): Do not use a label just before a statement. Problem reported by Bruno Haible (Bug#78032).	2025-04-27 23:42:49 -07:00
Paul Eggert	49760e9f50	doc: update Autoconf version	2025-04-27 23:42:49 -07:00
Paul Eggert	33ee12e587	build: use system help2man Instead of shipping an old ‘help2man’ that is not properly maintained, use the system’s ‘help2man’. It was already listed as a build prerequisite, and being configured via AM_MISSING_PROG. Problem for FreeBSD and NetBSD reported by Bruno Haible <https://bugs.gnu.org/72235>. * man/Makefile.am (EXTRA_DIST): Remove help2man. ($(dist_man1_MANS)): Do not depend on help2man. Use $(HELP2MAN) instead. * man/help2man: Remove.	2025-04-27 23:42:49 -07:00
Paul Eggert	45a4762bf3	sdiff: pacify gcc -flto -Wmaybe-uninitialized * src/sdiff.c (edit): Portmanteauize two locals into one, which arguably makes the code clearer, and anyway pacifies gcc -flto -Wmaybe-uninitialized with gcc (GCC) 15.0.1 20250329 (Red Hat 15.0.1-0) x86-64 (Bug#78019).	2025-04-23 11:46:37 -07:00
Paul Eggert	80053ab7b5	sdiff: continue → break * src/sdiff.c (edit): Don’t use ‘continue’ when a simple break from the switch will do.	2025-04-23 11:46:37 -07:00
Jim Meyering	d05765a8f1	maint: post-release administrivia * NEWS: Add header line for next release. * .prev-version: Record previous version. * cfg.mk (old_NEWS_hash): Auto-update.	2025-04-08 19:41:07 -07:00
Jim Meyering	16681a3cbc	version 3.12 * NEWS: Record release date.	2025-04-08 19:37:19 -07:00
Jim Meyering	6c92d5fb8f	tests: cmp: increase timeout to avoid failure on a very busy-IO system * tests/cmp: Increase timeout from 0.1 to 0.4s, to avoid false-failure on a system with lots of IO congestion. Reported by Nelson Beebe in https://lists.gnu.org/r/diffutils-devel/2025-04/msg00007.html	2025-04-08 13:44:18 -07:00
Jim Meyering	7e53977313	build: update gnulib to latest; and update bootstrap	2025-04-04 14:23:49 -07:00
Jim Meyering	53ba74998b	maint: ensure that new "make syntax-check"-run sc_codespell passes * cfg.mk (codespell_ignore_words_list): Ignore false-positive "words".	2025-03-28 08:11:20 -07:00
Jim Meyering	f180b5f4d4	maint: rather than exempt "hight" as a spelling false-positive... * src/diff3.c (output_diff3): Rename lowt,hight to low_t,high_t.	2025-03-27 21:34:25 -07:00
Paul Eggert	362a759cfb	tests: test for diff -y crash * tests/side-by-side-seq: New test. * tests/Makefile.am (TESTS): Add it.	2025-02-28 23:14:35 -08:00
Paul Eggert	e9f8e6a439	diff: fix allocation typo leading to crashes But reported by Nick Smallbone, with one-line fix by Collin Funk <https://bugs.gnu.org/76613>. * src/io.c (find_and_hash_each_line): Fix size computation.	2025-02-28 23:14:35 -08:00
Paul Eggert	58e734dedd	tests: make seq replacement more available This refactoring should let other future tests use ‘seq’. * tests/diff3 (seq): Move from here ... * tests/init.cfg: ... to here.	2025-02-28 23:14:35 -08:00
Paul Eggert	706116c651	maint: mention bug#76452 in NEWS	2025-02-21 23:10:06 -07:00
Collin Funk	6395d51a01	diff: add a test case for the recent empty file bug * tests/empty-file: New file. * tests/Makefile.am (TESTS): Add the test.	2025-02-21 23:03:38 -07:00
Paul Eggert	6ce0ebd033	diff: don't treat empty files as a different file type Reported by Kate Deplaix <kit-ty-kate@outlook.com> in <https://lists.gnu.org/r/bug-diffutils/2025-02/msg00005.html>. * src/diff.c (compare_prepped_files): Don't rely on string file type, as that might not agree with our idea of a file type.	2025-02-21 23:03:38 -07:00
Simon Josefsson	82cbd61848	cmp, diff, diff3, sdiff: support gnulib-l10n * src/cmp.c (main): Call bindtextdomain for gnulib-l10n. * src/diff.c (main): Likewise. * src/diff3.c (main): Likewise. * src/sdiff.c (main): Likewise.	2025-02-03 15:10:37 -08:00
Jim Meyering	41034e8398	maint: post-release administrivia * NEWS: Add header line for next release. * .prev-version: Record previous version. * cfg.mk (old_NEWS_hash): Auto-update.	2025-02-02 20:52:15 -08:00
 @ -1 +1 @@
 .10
 .12