- `make dist' now fails when tar fails, instead of exiting
successfully with a truncated archive.
+ - The filename-length-max=N option no longer rejects file names of
+ exactly N characters; as documented, only longer ones are.
+ (bug#81558)
+
+ - The manual no longer presents 99 characters as the portable limit
+ for file names in any archive format: it is the limit of the v7
+ format, whereas ustar, the default since Automake 1.18, stores
+ longer names. (bug#81557)
+
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
New in 1.18.1 (2025-06-25):
$transform{'DIST-TARGETS'} = join (' ', @dist_targets);
my $flm = option ('filename-length-max');
- my $filename_filter = $flm ? '.' x $flm->[1] : '';
+ my $filename_filter = $flm ? '.' x (1 + $flm->[1]) : '';
$output_rules .= file_contents ('distdir',
new Automake::Location,
Support for it will be removed altogether in Automake 2.0.
@trindex dist-tarZ
-@item @option{filename-length-max=99}
-@cindex Option, @option{filename-length-max=99}
-@opindex filename-length-max=99
-Abort if file names longer than 99 characters are found during
-@samp{make dist}. Such long file names are generally considered not to
-be portable in tarballs. See the @option{tar-v7} and @option{tar-ustar}
-options below. This option should be used in the top-level
+@item @option{filename-length-max=@var{max}}
+@cindex Option, @option{filename-length-max=@var{max}}
+@opindex filename-length-max=@var{max}
+Abort @samp{make dist} if the distribution contains file names longer
+than @var{max} characters; names of exactly @var{max} characters are
+accepted. What is measured is the name under which @command{tar} will
+store the file, so it includes the @file{@var{package}-@var{version}/}
+prefix.
+
+How long a file name may be depends on the archive format in use
+(@pxref{tar-formats}). The @option{tar-v7} format supports at most 99
+characters, hence the customary @option{filename-length-max=99}. The
+@option{tar-ustar} format, the default since Automake 1.18, stores file
+names of up to 256 characters, provided they can be split at a directory
+separator into a prefix of at most 155 characters and a remainder of at
+most 100; any name of at most 100 characters therefore fits, and
+@option{filename-length-max=155} is a safe choice as long as no single
+component of a file name exceeds 100 characters. The @option{tar-pax}
+format does not limit file name lengths at all. So, unless you also
+distribute a V7 archive, @option{filename-length-max=99} is stricter
+than necessary.
+
+This option should be used in the top-level
@file{Makefile.am} or as an argument of @code{AM_INIT_AUTOMAKE} in
@file{configure.ac}; it will be ignored otherwise. It will also be
ignored in sub-packages of nested packages (@pxref{Subpackages}).
! -type d ! -perm -444 -exec $(install_sh) -c -m a+r {} {} \; \
|| chmod -R a+r "$(distdir)"
if %?FILENAME_FILTER%
+## %FILENAME_FILTER% is one dot longer than the requested maximum, so
+## that it matches only the file names that exceed it.
@if test -z "$(am__skip_length_check)" && find "$(distdir)" -type f -print | \
grep '^%FILENAME_FILTER%' 1>&2; then \
- echo 'error: the above filenames are too long' 1>&2; \
+ echo 'error: the above filenames are too long' \
+ '(see the filename-length-max option)' 1>&2; \
exit 1; \
else :; fi
endif %?FILENAME_FILTER%
--- /dev/null
+#! /bin/sh
+# Copyright (C) 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
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+# The filename-length-max=N option must accept file names of exactly N
+# characters, and reject only the longer ones. See automake bug#81558.
+
+. test-init.sh
+
+echo AC_OUTPUT >> configure.ac
+
+# Long enough to be the longest file name of the distribution.
+long=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+
+mkdir dir
+: > dir/$long
+
+# The maximum we ask for is the length of the name under which tar would
+# store that file, that is, including the "$distdir/" prefix. Word
+# splitting gets rid of the padding some 'wc' implementations write.
+set -- $(printf '%s' "$distdir/dir/$long" | wc -c)
+max=$1
+echo "maximum file name length: $max" # For debugging.
+
+cat > Makefile.am << END
+AUTOMAKE_OPTIONS = filename-length-max=$max
+EXTRA_DIST = dir
+END
+
+$ACLOCAL
+$AUTOCONF
+$AUTOMAKE
+./configure
+
+# A file name of exactly $max characters is not too long.
+$MAKE dist
+test -f $distdir.tar.gz
+
+# One character more, and it is.
+: > dir/a$long
+run_make -E -e FAIL dist
+grep 'filenames are too long' stderr
+# And only that file gets reported.
+test 1 -eq $(grep -c "$long" stderr)
+
+:
t/extra-sources.sh \
t/extra.sh \
t/f90only.sh \
+t/filename-length-max.sh \
t/flavor.sh \
t/flibs.sh \
t/fn99.sh \
projects / thirdparty / automake.git / commitdiff
