gnulib-tool: properly list the LGPL3orGPLv2 license
* gnulib-tool (func_import): Adhere to the license guideline when
rewriting the license text to "LGPLv3+ or GPLv2":
https://www.gnu.org/prep/maintain/maintain.html#Licensing-of-GNU-Packages
KO Myung-Hun [Thu, 1 Dec 2016 10:52:46 +0000 (19:52 +0900)]
scandir: Fix _D_ALLOC_NAMLEN() on OS/2 kLIBC
On OS/2 kLIBC, d_name is not the last field of struct dirent. So
copying struct dirent according to the size calculated based on d_name
blows the fields after d_name up.
The correct way is to allocate the whole size of struct dirent.
* lib/scandir.c (_D_ALLOC_NAMLEN): Consider the fields after d_name on
OS/2 kLIBC.
Jim Meyering [Tue, 29 Nov 2016 18:45:46 +0000 (10:45 -0800)]
dfa: avoid new infinite loop
This would infloop: echo cx | LC_ALL=C grep -E 'c\b[x ]'
* lib/dfa.c (dfastate): When constructing a new state table, we could
initially declare that we had found a match, and later find that
constraints eliminate that possibility, yet continue to use the
now stale "matched" indicator. That would lead to an infinite loop.
The solution is to update "matched" when necessary.
Introduced by commit v0.1-983-g403adf1.
Norihiro Tanaka [Mon, 28 Nov 2016 13:26:07 +0000 (22:26 +0900)]
dfa: do not match middle of multibyte character
* lib/dfa.c (transit_state): If it fails in matching a single byte
character in a state including a period expression in a non-UTF8
multibyte locale, skip the trailing bytes.
(dfa_supported): Revert previous change.
Jim Meyering [Sun, 27 Nov 2016 23:36:51 +0000 (15:36 -0800)]
dfa: avoid false match in non-UTF8 multibyte locales
* lib/dfa.c (dfa_supported): Treat any non-UTF8 multibyte locale
as "not supported" so that callers will resort to using regex-based
matcher. This will surely hurt performance, but correctness trumps
performance here, and the affected locales are less and less relevant,
these days. See grep's bug report https://bugs.gnu.org/24975.
Mike Frysinger [Sun, 27 Nov 2016 03:52:00 +0000 (22:52 -0500)]
ptsname_r: leverage AC_HEADER_MAJOR
Like the mountlist module, ptsname_r uses makedev/major/minor,
so use the existing autoconf macro which will probe some headers
for use and set up some defines.
* lib/md4.c (md4_process_bytes): The existing define is made internal
in recent versions of glibc, so also use this new public define.
* lib/md5.c (md5_process_bytes): Likewise.
* lib/sha1.c (sha1_process_bytes): Likewise.
* lib/sha256.c (sha256_process_bytes): Likewise.
* lib/sha512.c (sha512_process_bytes): Likewise.
Pádraig Brady [Sat, 26 Nov 2016 15:39:11 +0000 (15:39 +0000)]
maint: use a more standard return from mbrtowc test
With this we can use this check in coreutils to find configure issues:
grep -E '(program exited with status 1$|core dumped)' config.log
* m4/mbrtowc.m4 (gl_MBRTOWC_C_LOCALE): Don't return 1
from the test program as this often indicates an
unhandled case in the test program.
(gl_MBRTOWC_INCOMPLETE_STATE): Likewise.
(gl_MBRTOWC_SANITYCHECK): Likewise.
(gl_MBRTOWC_NULL_ARG2): Likewise.
(gl_MBRTOWC_NUL_RETVAL): Likewise.
Paul Eggert [Sat, 26 Nov 2016 22:53:29 +0000 (14:53 -0800)]
freopen: work around glibc bug with closed fd
Work around glibc bug#15589, where freopen mishandles the case
where stdin etc. are already closed.
* doc/posix-functions/freopen.texi (freopen): Document the bug.
* lib/freopen.c (_GL_ALREADY_INCLUDING_STDIO_H): Define this
instead of __need_FILE, as the latter does not work with glibc.
Include <fcntl.h>, for open flags.
(rpl_freopen): Work around glibc bug.
* m4/freopen.m4 (gl_FUNC_FREOPEN): Check for bug.
* modules/freopen (Depends-on): Add fcntl-h.
* tests/test-freopen.c (main): Test for bug.
Paul Eggert [Fri, 25 Nov 2016 18:43:38 +0000 (10:43 -0800)]
dfa: fix glitches with on-demand states
Also, adjust commentary to better match new code.
Some of these glitches predate the recent change.
* lib/dfa.c (dfaanalyze): Clear trcount here, so that it counts
only non-initial states.
(dfastate): Rename locals to better match new roles.
Move them into nested scopes if this is easy.
Omit unnecessary cdalls to zeroset.
Simplify test for whether to throw in the positions of state 0.
Omit C99-ism (decl after statement) since Gawk still wants C89.
(build_state): Omit unnecessary test and assignment.
Fix some confusion that counted transition tables inaccurately
and could cause a memory leak.
(dfaexec_main): Redo to make it clearer to the compiler that
-1 and -2 are the only negative state numbers here.
Norihiro Tanaka [Fri, 25 Nov 2016 18:43:38 +0000 (10:43 -0800)]
dfa: addition of new state on demand
* src/dfa.c (dfastate): Add argument UC, the current input character.
Fill only a group including the character in transition table.
(realloc_trans_if_necessary): Add the dummy state which means that a
transition table is assigned but the next state is not assigned.
(build_state): Return the next state. All callers updated.
(transit_state_singlebyte): If we get the dummy state,
fill the transition table.
(dfaexec_main): Handle the dummy state.
(free_mbdata, dfafree): Consider the dummy state.
Daiki Ueno [Wed, 23 Nov 2016 11:46:09 +0000 (12:46 +0100)]
srclist: add "release" option
* config/srclist.txt: Change the format so that the first column
of each line points to the top-level directory of the source
archive.
* config/srclist-update: Accept "release" option that checks files
from the most recently tagged revision in the source archive.
Bruno Haible [Sun, 20 Nov 2016 12:24:27 +0000 (13:24 +0100)]
snippet/c++defs: Simplify _GL_CXXALIAS_* macros.
* build-aux/snippet/c++defs.h [__cplusplus && GNULIB_NAMESPACE]
(_GL_CXXALIAS_RPL_1, _GL_CXXALIAS_RPL_CAST_1,
_GL_CXXALIAS_SYS, _GL_CXXALIAS_SYS_CAST, _GL_CXXALIAS_SYS_CAST2):
Inline and remove member function 'rpl ()' of the wrapper struct.
Paul Eggert [Mon, 21 Nov 2016 04:16:29 +0000 (20:16 -0800)]
dfa: fix logic typo
Problem reported by Stephane Chazelas (Bug#24973).
* lib/dfa.c (using_simple_locale): Fix typo that caused some
non-simple locales like fr_FR to be treated as simple.
Jim Meyering [Sun, 20 Nov 2016 16:33:38 +0000 (08:33 -0800)]
fix test driver leaks: exclude, malloc, realloc
* tests/test-exclude.c (main): Fix trivial leak.
* tests/test-malloc-gnu.c (main): Likewise.
* tests/test-realloc-gnu.c (main): Likewise.
With these changes, grep's tests are now leak free.
I.e., running them with ASAN elicits no failure:
make CFLAGS='-O0 -ggdb3' AM_CFLAGS=-fsanitize=address \
AM_LDFLAGS='-fsanitize=address -static-libasan' check
Pedro Alves [Sat, 12 Nov 2016 16:22:54 +0000 (17:22 +0100)]
GNULIB_NAMESPACE::func need not pull in rpl_func
* build-aux/snippet/c++defs.h [__cplusplus && GNULIB_NAMESPACE]
(_GL_CXXALIAS_RPL_1, _GL_CXXALIAS_RPL_CAST_1, _GL_CXXALIAS_SYS)
(_GL_CXXALIAS_SYS_CAST, _GL_CXXALIAS_SYS_CAST2): Define a wrapper
struct instead of a function pointer.
Bruno Haible [Sun, 13 Nov 2016 03:03:39 +0000 (04:03 +0100)]
Relicense some modules under LGPLv2+.
Paul Eggert's approval is in
http://lists.gnu.org/archive/html/bug-gnulib/2016-11/msg00037.html.
Eric Blake's approval is in
http://lists.gnu.org/archive/html/bug-gnulib/2016-11/msg00042.html.
Ludovic Courtès's approval is in
http://lists.gnu.org/archive/html/bug-gnulib/2016-11/msg00038.html.
* modules/isnand-nolibm (License): Change to LGPLv2+.
* modules/isnanf-nolibm (License): Likewise.
* modules/isnanl-nolibm (License): Likewise.
Bruno Haible [Sun, 13 Nov 2016 02:58:45 +0000 (03:58 +0100)]
Relicense some modules under LGPLv2+.
lib/float+.h is already under LGPLv2+ since 2007-07-13, per
modules/vasnprintf.
Paolo Bonzini's approval for lib/frexp.c and lib/frexpl.c is in
http://lists.gnu.org/archive/html/bug-gnulib/2016-11/msg00074.html.
All other significant changes to the files in lib/ of these modules
are from me.
* modules/memcmp2 (License): Change to LGPLv2+.
* modules/amemxfrm (License): Likewise.
* modules/fpieee (License): Likewise.
* modules/fpucw (License): Likewise.
* modules/frexp-nolibm (License): Likewise.
* modules/frexpl-nolibm (License): Likewise.
* modules/printf-frexp (License): Likewise.
* modules/printf-frexpl (License): Likewise.
* modules/printf-safe (License): Likewise.
* modules/signbit (License): Likewise.
Pedro Alves [Mon, 14 Nov 2016 23:08:21 +0000 (23:08 +0000)]
snippet/c++defs: fix real-floating arg functions in C++ mode
Also, define isfinite, isinf, isnan, signbit in the gnulib
namespace instead of in the global namespace.
* build-aux/snippet/c++defs.h (_GL_BEGIN_NAMESPACE)
(_GL_END_NAMESPACE): New.
* lib/math.in.h (_GL_MATH_CXX_REAL_FLOATING_DECL_2): Use them.
(isfinite, isinf, isnan, signbit) [__cplusplus &&
GNULIB_NAMESPACE]: Define them in the GNULIB_NAMESPACE namespace
instead of in the global namespace.
* tests/test-math-c++.cc: Check that the isfinite, isinf, isnan,
signbit overloads exist in the GNULIB_NAMESPACE namespace, instead
of in the global namespace.
Jim Meyering [Mon, 14 Nov 2016 02:15:36 +0000 (18:15 -0800)]
strftime: don't use __THROW
Each use of __THROW would provoke this from gcc-7-to-be:
lib/strftime.c:371:1: warning: '__leaf__' attribute has no effect \
on unit local functions [-Wattributes]
static int iso_week_days (int, int) __THROW;
^~~~~~
* lib/strftime.c (__THROW): Don't define.
Remove each use of __THROW.
* lib/strftime.c (memcpy_lowcase, memcpy_uppcase): Remove __THROW.
(tm_diff, iso_week_days, __strftime_internal): Likewise.
Paul Eggert [Tue, 15 Nov 2016 03:48:28 +0000 (19:48 -0800)]
obstack: port to gcc -fcheck-pointer-bounds
Problem found by 'make check' failure on bleeding-edge coreutils
on an MPX-enabled CPU (Intel Core i3-7100U) running GCC (Ubuntu
6.2.0-5ubuntu12), configured via "./configure
--enable-gcc-warnings CFLAGS='-mmpx -fcheck-pointer-bounds -g3
-O2' LDFLAGS='-static-libmpx -static-libmpxwrappers'".
* lib/obstack.h (__FLEXIBLE_ARRAY_MEMBER):
New macro, copied from fts_.h.
(struct _obstack_chunk.contents): Use it.
Eric Blake [Mon, 14 Nov 2016 21:36:51 +0000 (15:36 -0600)]
strerror_r-posix: Another fix, for HAVE_DECL_STRERROR_R on mingw
Commit 5ddd9d7 improved strerror_r on glibc systems (where
STRERROR_R_CHAR_P was defined twice with different values), but
missed mingw systems (where HAVE_DECL_STRERROR_R is now defined
twice with different values). Avoid the AC_CHECK_DECLS[_ONCE]
and AC_CHECK_FUNCS[_ONCE] m4 macros that call AC_DEFINE under the
hood, and instead limit our checks to just setting shell witnesses,
so that compilation on mingw doesn't trigger warnings (and mess up
subsequent tests that use -Werror) about a redefined C preprocessor
macro.
* m4/strerror_r.m4 (gl_FUNC_STRERROR_R, gl_FUNC_STRERROR_R_WORKS):
Avoid calling macros that may supply a conflicting AC_DEFINE().
Bruno Haible [Sun, 13 Nov 2016 03:12:26 +0000 (04:12 +0100)]
gnulib-tool: Support for the dual "LGPLv3+ or GPLv2" license.
* gnulib-tool (--lgpl): Accept value 3orGPLv2.
(func_import): Extend determination of license_incompatibilities.
(func_create_testdir): Extend table of license compatibility. Handle
also the licenses GPLv3+, GPL, LGPLv3+.
Paul Eggert [Sun, 13 Nov 2016 01:26:39 +0000 (17:26 -0800)]
Merge strftime.c changes from glibc
This incorporates:
2007-10-16 [BZ #5184] Add tzset_called argument
2008-06-13 [BZ #6612] pass reference to tzset_called around
2009-10-30 Implement Burmese language locale for Myanmar
2010-01-09 Add support for XPG7 testing
2015-09-26 [BZ #18985] out of range data to strftime() causes a segfault
2015-10-20 Convert miscellaneous function definitions to prototype style
* lib/strftime.c: Copy glibc license, since gnulib-tool rewrites
it anyway and this lessens the difference between gnulib and glibc.
(USE_IN_EXTENDED_LOCALE_MODEL) [_LIBC]: Define.
(__THROW): Define if standard headers do not.
(LOCALE_PARAM): Rename from LOCALE_PARAM_PROTO. All uses changed.
(memcpy_locase, memcpy_uppcase, tm_diff, __strftime_internal):
Declare with __THROW.
(__strftime_internal): Rename from strftime_case_. Add arg for
whether tzset is called. All uses changed. Call tzset at most
once. Allow %OC, for Burmese.
(a_wkday, f_wkday, a_month, f_month) [_NL_CURRENT]:
Don't assume values are in range.
Eric Blake [Fri, 4 Nov 2016 19:06:39 +0000 (14:06 -0500)]
strerror_r-posix: Fix override of AC_FUNC_STRERROR_R
Requiring autoconf's AC_FUNC_STRERROR_R and then calling AC_DEFINE
ourselves leads to two insertions of #define STRERROR_R_CHAR_P
in confdefs.h, but with different values (at least on glibc). This
in turn sparks a gcc warning about redeclaring the macro, and kills
any subsequent tests that use -Werror (which now error because of
the conflicting define, whether or not the test used to error).
A better approach is to replace the autoconf macro with a version
of our own that doesn't probe anything, so that the AC_DEFINE is
reached exactly once.
* m4/strerror_r.m4 (AC_FUNC_STRERROR_R): New override.
(gl_FUNC_STRERROR_R): Don't reuse AC_DEFINE() with a potentially
different value.
Pedro Alves [Sat, 12 Nov 2016 16:22:54 +0000 (16:22 +0000)]
GNULIB_NAMESPACE::func need not pull in rpl_func
* build-aux/snippet/c++defs.h [__cplusplus && GNULIB_NAMESPACE]
(_GL_CXXALIAS_RPL_1, _GL_CXXALIAS_RPL_CAST_1, _GL_CXXALIAS_SYS)
(_GL_CXXALIAS_SYS_CAST, _GL_CXXALIAS_SYS_CAST2): Define a wrapper
struct instead of a function pointer.
* m4/manywarnings.m4: Fix -Wno-missing-field-initializers detection
to be independent of -Wunused-variable. I.E. ensure the latter
warning doesn't occur so that detection of the former is accurate.
Pádraig Brady [Mon, 7 Nov 2016 12:50:24 +0000 (12:50 +0000)]
non-recursive-gnulib-prefix-hack: revert use of parameterized 'lib' dir
This reverts commit df6f91c as the evaluation of the passed shell
variable happens at the wrong time in the references generated by
m4/non-recursive-gnulib-prefix-hack.m4
Revert to the hardcoded "lib/".
Paul Eggert [Fri, 4 Nov 2016 04:34:58 +0000 (21:34 -0700)]
intprops: port to older XL C
Problem reported by Alexander Samoilov in:
http://lists.gnu.org/archive/html/bug-gnulib/2016-10/msg00166.html
http://savannah.nongnu.org/bugs/?49448
* lib/intprops.h (_GL_HAVE___TYPEOF__) [__IBM__TYPEOF__]:
Define to 1 only for XL C 12.1 or later, since this bug
occurs in XL C for AIX 6.0 but not in 12.1.
Paul Eggert [Tue, 1 Nov 2016 15:55:17 +0000 (08:55 -0700)]
utimensat: remove FIXME for old Linux kernels
* lib/utimensat.c (rpl_utimensat): Update FIXME comment.
* m4/utimensat.m4 (gl_FUNC_UTIMENSAT): Belatedy do a "simplify
this in 2012" FIXME, by assuming the file system bug is absent
unless demonstrated to be present. We no longer need to worry
about Linux kernel 2.6.32 when building with newer kernels.
Bruno Haible [Sun, 16 Oct 2016 20:11:32 +0000 (22:11 +0200)]
qsort_r: Fix macrology for platforms that lack the function.
* m4/stdlib_h.m4 (gl_STDLIB_H): Check for qsort_r.
(gl_STDLIB_H_DEFAULTS): Initialize HAVE_QSORT_R.
* modules/stdlib (Makefile.am): Substitute HAVE_QSORT_R.
* lib/stdlib.in.h (qsort_r): Provide declaration if the function does
not exist.
* m4/qsort_r.m4 (gl_FUNC_QSORT_R): Use AC_CHECK_FUNCS to test whether
the function exists.
* modules/qsort_r: Add comments.
See Bug#24805.
* lib/getprogname.c (getprogname) [__hpux]: Port.
* tests/test-getprogname.c (STREQ) [__hpux]:
Special-case for HP-UX limitations on program name length.
Bruno Haible [Sun, 16 Oct 2016 15:45:52 +0000 (17:45 +0200)]
Fix conflict between strerror_r-posix module and AC_FUNC_STRERROR_R.
* m4/strerror_r.m4 (gl_FUNC_STRERROR_R): Override the values set by the
AC_FUNC_STRERROR_R macro. Define HAVE_DECL_STRERROR_R_ORIG.
* lib/strerror_r.c: Use HAVE_DECL_STRERROR_R_ORIG instead of
HAVE_DECL_STRERROR_R.
Paul Eggert [Tue, 25 Oct 2016 21:59:29 +0000 (14:59 -0700)]
diffseq: restore TOO_EXPENSIVE heuristic
* lib/diffseq.h: Problem with diffutils reported by Andreas Schwab
(Bug#24715). The simplest solution is to restore the
TOO_EXPENSIVE heuristic that I added to GNU diff in 1993, while
using a higher threshold to avoid Bug#16848 on smaller files.
* lib/diffseq.h (struct context): Restore member too_expensive.
(struct partition): Restore members lo_minimal, hi_minimal.
(diag, compareseq): Restore arg find_minimal. All uses changed.
(diag): Restore the TOO_EXPENSIVE heuristic that I added back in
1993 to make 'diff' run faster (but not as well) on large inputs,
but use a threshold of 4096 instead of the old 256.
* lib/fstrcmp.c (strcmp_bounded):
* lib/git-merge-changelog.c (compute_differences):
Adjust to diffseq.h changes.
Bruno Haible [Sun, 16 Oct 2016 14:59:45 +0000 (16:59 +0200)]
Fix some "gcc -Wall" warnings.
* tests/test-ffsl.c (main): Use variable x, not i.
* tests/test-posix_spawn3.c (parent_main): Consider the return value of
freopen.
* tests/test-sethostname1.c (main): Explicitly ignore the return value
of sethostname.
Paul Eggert [Thu, 20 Oct 2016 22:35:02 +0000 (15:35 -0700)]
quotearg-tests: pacify gcc -Wall
Problem reported by Bruno Haible in:
http://lists.gnu.org/archive/html/bug-gnulib/2016-10/msg00066.html
* tests/test-quotearg-simple.c (use_quote_double_quotes): Move here ...
* tests/test-quotearg.h: ... from here.
Jim Meyering [Thu, 20 Oct 2016 16:32:54 +0000 (09:32 -0700)]
printf.m4: fix a bug in detecting printf %j support
* m4/printf.m4 (gl_PRINTF_SIZES_C99): Fail any system for which
uintmax_t is defined in neither stdint.h nor inttypes.h.
Before, this macro might have mistakenly set
gl_cv_func_printf_sizes_c99=yes on such a system.
Spotted by Zev Weiss.
Paul Eggert [Thu, 20 Oct 2016 06:46:10 +0000 (23:46 -0700)]
sched: substitute HAVE_SYS_CDEFS_H too
Problem reported by Tom G. Christensen in:
http://lists.gnu.org/archive/html/bug-gnulib/2016-10/msg00084.html
* m4/sched_h.m4 (gl_SCHED_H): Set and substitute HAVE_SYS_CDEFS_H.
* modules/sched (Depends-on): Substitute HAVE_SYS_CDEFS_H.
Pádraig Brady [Tue, 18 Oct 2016 20:00:07 +0000 (13:00 -0700)]
quotearg: never write beyond the returned length
* lib/quotearg.c (quotearg_buffer_restyled): Switch to a read-only
scan of the string when we initially encounter a single quote when
shell quoting, so that if we then switch to a more concise quoting method
we will not have written beyond that returned length.
This is significant for sh-quote, which has separate routines
to determine the length and do the actual quoting.
* tests/test-quotearg.h: Reinstate the buffer bounds checking
now that we never write more than the returned length.
Pádraig Brady [Sun, 16 Oct 2016 21:51:30 +0000 (22:51 +0100)]
quotearg: fix stale tests
* tests/test-quotearg.c [locale_results]: Add the missing str7
entries to the expected results.
tests/test-system-quote-main.c (check_one): Don't enforce that we
don't write beyond the returned length, since that's no longer the
case if we switch to a more concise quoting style.
* tests/test-sh-quote.c (check_one): Likewise.
(main): Adjust for the new more concise quoting style.
Reported by Bruno Haible.
Jim Meyering [Wed, 12 Oct 2016 19:30:07 +0000 (12:30 -0700)]
test-stdint: use _GL_VERIFY rather than "verify" for some tests
* tests/test-stdint.c (verify_width): Implement with _GL_VERIFY
and an abbreviated diagnostic rather than verify with the full one,
because the full-length strings would evoke warnings from gcc with
-Woverlength-strings.
Paul Eggert [Thu, 13 Oct 2016 18:16:40 +0000 (11:16 -0700)]
stdint: port SIZE_MAX to glibc s390
Problem reported by Eric Blake in:
http://lists.gnu.org/archive/html/bug-gnulib/2016-10/msg00031.html
* doc/posix-headers/stdint.texi (stdint.h): Document the fix.
* m4/stdint.m4 (gl_STDINT_H): Check that SIZE_MAX has the
correct type, if possible.
Jim Meyering [Wed, 5 Oct 2016 17:43:09 +0000 (10:43 -0700)]
long-options: avoid new GCC 7 warning from -Wimplicit-fallthrough
* lib/long-options.c (parse_long_options): Add a break statement
to avoid this new warning/failure:
$ CFLAGS='-O -Werror=implicit-fallthrough' ./gnulib-tool \
--create-testdir --dir=/t/x --with-tests --test long-options
../../gllib/long-options.c: In function 'parse_long_options':
../../gllib/long-options.c:66:12: error: this statement may \
fall through [-Werror=implicit-fallthrough]
(*usage_func) (EXIT_SUCCESS);
~^~~~~~~~~~~~~~~~~~~~~~~~~~~
Jim Meyering [Wed, 5 Oct 2016 16:13:55 +0000 (09:13 -0700)]
utimecmp: avoid new GCC 7 warning from -Wbool-operation
Testing this module would fail when using GCC 7 like this:
$ CFLAGS='-O -Werror=bool-operation' ./gnulib-tool --create-testdir \
--dir=/tmp/x --with-tests --test utimecmp
../../gllib/utimecmp.c: In function ‘utimecmp’:
../../gllib/utimecmp.c:291:36: error: ‘~’ on a boolean expression \
[-Werror=bool-operation]
time_t s = src_s & ~ (res == 2 * BILLION);
^
../../gllib/utimecmp.c:370:16: error: ‘~’ on a boolean expression \
[-Werror=bool-operation]
src_s &= ~ (res == 2 * BILLION);
^
* lib/utimecmp.c (utimecmp): Do not apply "~" to a boolean.
Instead, make it explicit that we intend to apply it to 0 or 1.