s/padwidht/padwidth/ in the summary line On 26/04/25 06:56 +0200, Tomasz Kamiński wrote:
The _Padding_sink was behaving incorrectly, when the predicated width (based on
predicted?
code units count) was higher than _M_maxwidth, but lower than _M_padwidth. In this case _M_update() returned without calling _M_force_update() and computing field width for Unicode encoding, because _M_buffering() returned 'true'. As a consequence we switched to _M_ignoring() mode, while storing a sequence with more code units but smaller field width than _M_maxwidth. We now call _M_force_update() if predicted width is greater or equal to either _M_padwidth or _M_maxwidth. This happened for existing test case on 32bit architecture. libstdc++-v3/ChangeLog: * include/std/format (_Padding_sink::_M_update): Fixed condition for calling _M_force_update. * testsuite/std/format/debug.cc: Add test that reproducers this issue
s/reproducers/reproduces/
on 64bit architecture. * testsuite/std/format/ranges/sequence.cc: Another edge value test. --- Fixed some types in message and replaced > with >= in check. Tested on x86_64-linux with unix{,-std=c++98,-std=gnu++11,-std=gnu++20, -D_GLIBCXX_USE_CXX11_ABI=0/-D_GLIBCXX_DEBUG,-D_GLIBCXX_ASSERTIONS/-m32,-std=gnu++23}. OK for trunk?
I have stepped through the code and satisfied myself that this is correct now. OK for trunk, thanks.
libstdc++-v3/include/std/format | 7 ++++--- libstdc++-v3/testsuite/std/format/debug.cc | 9 +++++++++ libstdc++-v3/testsuite/std/format/ranges/sequence.cc | 9 +++++++++ 3 files changed, 22 insertions(+), 3 deletions(-) diff --git a/libstdc++-v3/include/std/format b/libstdc++-v3/include/std/format index 69d8d189db6..b3794b64b59 100644 --- a/libstdc++-v3/include/std/format +++ b/libstdc++-v3/include/std/format @@ -3697,9 +3697,10 @@ namespace __format _M_update(size_t __new) { _M_printwidth += __new; - if (_M_buffering()) - return true; - return _M_force_update(); + // Compute estimated witdth, to see if is not reduced.
s/witdth/width/
+ if (_M_printwidth >= _M_padwidth || _M_printwidth >= _M_maxwidth) + return _M_force_update(); + return true; } void diff --git a/libstdc++-v3/testsuite/std/format/debug.cc b/libstdc++-v3/testsuite/std/format/debug.cc index d3402f80f4b..6165a295496 100644 --- a/libstdc++-v3/testsuite/std/format/debug.cc +++ b/libstdc++-v3/testsuite/std/format/debug.cc @@ -596,6 +596,10 @@ void test_padding() VERIFY( strip_prefix(resv, 48, '*') ); VERIFY( resv == inv ); + resv = res = std::format("{:*>300.200s}", in); + VERIFY( strip_prefix(resv, 108, '*') ); + VERIFY( resv == inv ); + resv = res = std::format("{:*>240.200s}", in); VERIFY( strip_prefix(resv, 48, '*') ); VERIFY( resv == inv ); @@ -678,6 +682,11 @@ void test_padding() VERIFY( strip_quotes(resv) ); VERIFY( resv == inv ); + resv = res = std::format("{:*>300.200?}", in); + VERIFY( strip_prefix(resv, 106, '*') ); + VERIFY( strip_quotes(resv) ); + VERIFY( resv == inv ); + resv = res = std::format("{:*>240.200?}", in); VERIFY( strip_prefix(resv, 46, '*') ); VERIFY( strip_quotes(resv) ); diff --git a/libstdc++-v3/testsuite/std/format/ranges/sequence.cc b/libstdc++-v3/testsuite/std/format/ranges/sequence.cc index 75fe4c19a52..32242860f10 100644 --- a/libstdc++-v3/testsuite/std/format/ranges/sequence.cc +++ b/libstdc++-v3/testsuite/std/format/ranges/sequence.cc @@ -295,6 +295,15 @@ void test_padding() resv = res = std::format("{:*>10n:}", vs); VERIFY( check_elems(resv, false) ); + resv = res = std::format("{:*>256}", vs); + VERIFY( strip_prefix(resv, 48, '*') ); + VERIFY( strip_squares(resv) ); + VERIFY( check_elems(resv, true) ); + + resv = res = std::format("{:*>256n}", vs); + VERIFY( strip_prefix(resv, 50, '*') ); + VERIFY( check_elems(resv, true) ); + resv = res = std::format("{:*>240}", vs); VERIFY( strip_prefix(resv, 32, '*') ); VERIFY( strip_squares(resv) ); -- 2.49.0