From 36ccdba805f1322c23714dbeb227fb632b54ae45 Mon Sep 17 00:00:00 2001 From: Colin Cross Date: Mon, 24 Jan 2022 20:27:14 -0800 Subject: Update webrtc's abseil-cpp Copy external/abseil-cpp into webrtc to update to version 20211102.0 to pick up changes that fix compiling against musl libc. Bug: 190084016 Test: m USE_HOST_MUSL=true host-native Test: m checkbuild Change-Id: I0ab600cd8db93a55eda8358cdbecd21c2f78d8fb --- .../absl/time/internal/cctz/src/time_zone_info.cc | 369 ++++++++++++--------- 1 file changed, 219 insertions(+), 150 deletions(-) (limited to 'third_party/abseil-cpp/absl/time/internal/cctz/src/time_zone_info.cc') diff --git a/third_party/abseil-cpp/absl/time/internal/cctz/src/time_zone_info.cc b/third_party/abseil-cpp/absl/time/internal/cctz/src/time_zone_info.cc index f1697cdf04..4f175d95fc 100644 --- a/third_party/abseil-cpp/absl/time/internal/cctz/src/time_zone_info.cc +++ b/third_party/abseil-cpp/absl/time/internal/cctz/src/time_zone_info.cc @@ -39,11 +39,12 @@ #include #include #include +#include #include -#include #include #include #include +#include #include "absl/base/config.h" #include "absl/time/internal/cctz/include/cctz/civil_time.h" @@ -83,6 +84,27 @@ const std::int_least32_t kSecsPerYear[2] = { 366 * kSecsPerDay, }; +// Convert a cctz::weekday to a POSIX TZ weekday number (0==Sun, ..., 6=Sat). +inline int ToPosixWeekday(weekday wd) { + switch (wd) { + case weekday::sunday: + return 0; + case weekday::monday: + return 1; + case weekday::tuesday: + return 2; + case weekday::wednesday: + return 3; + case weekday::thursday: + return 4; + case weekday::friday: + return 5; + case weekday::saturday: + return 6; + } + return 0; /*NOTREACHED*/ +} + // Single-byte, unsigned numeric values are encoded directly. inline std::uint_fast8_t Decode8(const char* cp) { return static_cast(*cp) & 0xff; @@ -188,15 +210,13 @@ bool TimeZoneInfo::ResetToBuiltinUTC(const seconds& offset) { tt.is_dst = false; tt.abbr_index = 0; - // We temporarily add some redundant, contemporary (2013 through 2023) + // We temporarily add some redundant, contemporary (2015 through 2025) // transitions for performance reasons. See TimeZoneInfo::LocalTime(). // TODO: Fix the performance issue and remove the extra transitions. transitions_.clear(); transitions_.reserve(12); for (const std::int_fast64_t unix_time : { - -(1LL << 59), // BIG_BANG - 1356998400LL, // 2013-01-01T00:00:00+00:00 - 1388534400LL, // 2014-01-01T00:00:00+00:00 + -(1LL << 59), // a "first half" transition 1420070400LL, // 2015-01-01T00:00:00+00:00 1451606400LL, // 2016-01-01T00:00:00+00:00 1483228800LL, // 2017-01-01T00:00:00+00:00 @@ -206,7 +226,8 @@ bool TimeZoneInfo::ResetToBuiltinUTC(const seconds& offset) { 1609459200LL, // 2021-01-01T00:00:00+00:00 1640995200LL, // 2022-01-01T00:00:00+00:00 1672531200LL, // 2023-01-01T00:00:00+00:00 - 2147483647LL, // 2^31 - 1 + 1704067200LL, // 2024-01-01T00:00:00+00:00 + 1735689600LL, // 2025-01-01T00:00:00+00:00 }) { Transition& tr(*transitions_.emplace(transitions_.end())); tr.unix_time = unix_time; @@ -217,8 +238,8 @@ bool TimeZoneInfo::ResetToBuiltinUTC(const seconds& offset) { default_transition_type_ = 0; abbreviations_ = FixedOffsetToAbbr(offset); - abbreviations_.append(1, '\0'); // add NUL - future_spec_.clear(); // never needed for a fixed-offset zone + abbreviations_.append(1, '\0'); + future_spec_.clear(); // never needed for a fixed-offset zone extended_ = false; tt.civil_max = LocalTime(seconds::max().count(), tt).cs; @@ -259,21 +280,6 @@ std::size_t TimeZoneInfo::Header::DataLength(std::size_t time_len) const { return len; } -// Check that the TransitionType has the expected offset/is_dst/abbreviation. -void TimeZoneInfo::CheckTransition(const std::string& name, - const TransitionType& tt, - std::int_fast32_t offset, bool is_dst, - const std::string& abbr) const { - if (tt.utc_offset != offset || tt.is_dst != is_dst || - &abbreviations_[tt.abbr_index] != abbr) { - std::clog << name << ": Transition" - << " offset=" << tt.utc_offset << "/" - << (tt.is_dst ? "DST" : "STD") - << "/abbr=" << &abbreviations_[tt.abbr_index] - << " does not match POSIX spec '" << future_spec_ << "'\n"; - } -} - // zic(8) can generate no-op transitions when a zone changes rules at an // instant when there is actually no discontinuity. So we check whether // two transitions have equivalent types (same offset/is_dst/abbr). @@ -282,117 +288,108 @@ bool TimeZoneInfo::EquivTransitions(std::uint_fast8_t tt1_index, if (tt1_index == tt2_index) return true; const TransitionType& tt1(transition_types_[tt1_index]); const TransitionType& tt2(transition_types_[tt2_index]); - if (tt1.is_dst != tt2.is_dst) return false; if (tt1.utc_offset != tt2.utc_offset) return false; + if (tt1.is_dst != tt2.is_dst) return false; if (tt1.abbr_index != tt2.abbr_index) return false; return true; } +// Find/make a transition type with these attributes. +bool TimeZoneInfo::GetTransitionType(std::int_fast32_t utc_offset, bool is_dst, + const std::string& abbr, + std::uint_least8_t* index) { + std::size_t type_index = 0; + std::size_t abbr_index = abbreviations_.size(); + for (; type_index != transition_types_.size(); ++type_index) { + const TransitionType& tt(transition_types_[type_index]); + const char* tt_abbr = &abbreviations_[tt.abbr_index]; + if (tt_abbr == abbr) abbr_index = tt.abbr_index; + if (tt.utc_offset == utc_offset && tt.is_dst == is_dst) { + if (abbr_index == tt.abbr_index) break; // reuse + } + } + if (type_index > 255 || abbr_index > 255) { + // No index space (8 bits) available for a new type or abbreviation. + return false; + } + if (type_index == transition_types_.size()) { + TransitionType& tt(*transition_types_.emplace(transition_types_.end())); + tt.utc_offset = static_cast(utc_offset); + tt.is_dst = is_dst; + if (abbr_index == abbreviations_.size()) { + abbreviations_.append(abbr); + abbreviations_.append(1, '\0'); + } + tt.abbr_index = static_cast(abbr_index); + } + *index = static_cast(type_index); + return true; +} + // Use the POSIX-TZ-environment-variable-style string to handle times // in years after the last transition stored in the zoneinfo data. -void TimeZoneInfo::ExtendTransitions(const std::string& name, - const Header& hdr) { +bool TimeZoneInfo::ExtendTransitions() { extended_ = false; - bool extending = !future_spec_.empty(); + if (future_spec_.empty()) return true; // last transition prevails PosixTimeZone posix; - if (extending && !ParsePosixSpec(future_spec_, &posix)) { - std::clog << name << ": Failed to parse '" << future_spec_ << "'\n"; - extending = false; - } - - if (extending && posix.dst_abbr.empty()) { // std only - // The future specification should match the last/default transition, - // and that means that handling the future will fall out naturally. - std::uint_fast8_t index = default_transition_type_; - if (hdr.timecnt != 0) index = transitions_[hdr.timecnt - 1].type_index; - const TransitionType& tt(transition_types_[index]); - CheckTransition(name, tt, posix.std_offset, false, posix.std_abbr); - extending = false; - } - - if (extending && hdr.timecnt < 2) { - std::clog << name << ": Too few transitions for POSIX spec\n"; - extending = false; - } - - if (!extending) { - // Ensure that there is always a transition in the second half of the - // time line (the BIG_BANG transition is in the first half) so that the - // signed difference between a civil_second and the civil_second of its - // previous transition is always representable, without overflow. - const Transition& last(transitions_.back()); - if (last.unix_time < 0) { - const std::uint_fast8_t type_index = last.type_index; - Transition& tr(*transitions_.emplace(transitions_.end())); - tr.unix_time = 2147483647; // 2038-01-19T03:14:07+00:00 - tr.type_index = type_index; - } - return; // last transition wins + if (!ParsePosixSpec(future_spec_, &posix)) return false; + + // Find transition type for the future std specification. + std::uint_least8_t std_ti; + if (!GetTransitionType(posix.std_offset, false, posix.std_abbr, &std_ti)) + return false; + + if (posix.dst_abbr.empty()) { // std only + // The future specification should match the last transition, and + // that means that handling the future will fall out naturally. + return EquivTransitions(transitions_.back().type_index, std_ti); } + // Find transition type for the future dst specification. + std::uint_least8_t dst_ti; + if (!GetTransitionType(posix.dst_offset, true, posix.dst_abbr, &dst_ti)) + return false; + // Extend the transitions for an additional 400 years using the // future specification. Years beyond those can be handled by // mapping back to a cycle-equivalent year within that range. - // zic(8) should probably do this so that we don't have to. - // TODO: Reduce the extension by the number of compatible - // transitions already in place. - transitions_.reserve(hdr.timecnt + 400 * 2 + 1); - transitions_.resize(hdr.timecnt + 400 * 2); + // We may need two additional transitions for the current year. + transitions_.reserve(transitions_.size() + 400 * 2 + 2); extended_ = true; - // The future specification should match the last two transitions, - // and those transitions should have different is_dst flags. Note - // that nothing says the UTC offset used by the is_dst transition - // must be greater than that used by the !is_dst transition. (See - // Europe/Dublin, for example.) - const Transition* tr0 = &transitions_[hdr.timecnt - 1]; - const Transition* tr1 = &transitions_[hdr.timecnt - 2]; - const TransitionType* tt0 = &transition_types_[tr0->type_index]; - const TransitionType* tt1 = &transition_types_[tr1->type_index]; - const TransitionType& dst(tt0->is_dst ? *tt0 : *tt1); - const TransitionType& std(tt0->is_dst ? *tt1 : *tt0); - CheckTransition(name, dst, posix.dst_offset, true, posix.dst_abbr); - CheckTransition(name, std, posix.std_offset, false, posix.std_abbr); - - // Add the transitions to tr1 and back to tr0 for each extra year. - last_year_ = LocalTime(tr0->unix_time, *tt0).cs.year(); + const Transition& last(transitions_.back()); + const std::int_fast64_t last_time = last.unix_time; + const TransitionType& last_tt(transition_types_[last.type_index]); + last_year_ = LocalTime(last_time, last_tt).cs.year(); bool leap_year = IsLeap(last_year_); - const civil_day jan1(last_year_, 1, 1); - std::int_fast64_t jan1_time = civil_second(jan1) - civil_second(); - int jan1_weekday = (static_cast(get_weekday(jan1)) + 1) % 7; - Transition* tr = &transitions_[hdr.timecnt]; // next trans to fill - if (LocalTime(tr1->unix_time, *tt1).cs.year() != last_year_) { - // Add a single extra transition to align to a calendar year. - transitions_.resize(transitions_.size() + 1); - assert(tr == &transitions_[hdr.timecnt]); // no reallocation - const PosixTransition& pt1(tt0->is_dst ? posix.dst_end : posix.dst_start); - std::int_fast64_t tr1_offset = TransOffset(leap_year, jan1_weekday, pt1); - tr->unix_time = jan1_time + tr1_offset - tt0->utc_offset; - tr++->type_index = tr1->type_index; - tr0 = &transitions_[hdr.timecnt]; - tr1 = &transitions_[hdr.timecnt - 1]; - tt0 = &transition_types_[tr0->type_index]; - tt1 = &transition_types_[tr1->type_index]; - } - const PosixTransition& pt1(tt0->is_dst ? posix.dst_end : posix.dst_start); - const PosixTransition& pt0(tt0->is_dst ? posix.dst_start : posix.dst_end); - for (const year_t limit = last_year_ + 400; last_year_ < limit;) { - last_year_ += 1; // an additional year of generated transitions + const civil_second jan1(last_year_); + std::int_fast64_t jan1_time = jan1 - civil_second(); + int jan1_weekday = ToPosixWeekday(get_weekday(jan1)); + + Transition dst = {0, dst_ti, civil_second(), civil_second()}; + Transition std = {0, std_ti, civil_second(), civil_second()}; + for (const year_t limit = last_year_ + 400;; ++last_year_) { + auto dst_trans_off = TransOffset(leap_year, jan1_weekday, posix.dst_start); + auto std_trans_off = TransOffset(leap_year, jan1_weekday, posix.dst_end); + dst.unix_time = jan1_time + dst_trans_off - posix.std_offset; + std.unix_time = jan1_time + std_trans_off - posix.dst_offset; + const auto* ta = dst.unix_time < std.unix_time ? &dst : &std; + const auto* tb = dst.unix_time < std.unix_time ? &std : &dst; + if (last_time < tb->unix_time) { + if (last_time < ta->unix_time) transitions_.push_back(*ta); + transitions_.push_back(*tb); + } + if (last_year_ == limit) break; jan1_time += kSecsPerYear[leap_year]; jan1_weekday = (jan1_weekday + kDaysPerYear[leap_year]) % 7; - leap_year = !leap_year && IsLeap(last_year_); - std::int_fast64_t tr1_offset = TransOffset(leap_year, jan1_weekday, pt1); - tr->unix_time = jan1_time + tr1_offset - tt0->utc_offset; - tr++->type_index = tr1->type_index; - std::int_fast64_t tr0_offset = TransOffset(leap_year, jan1_weekday, pt0); - tr->unix_time = jan1_time + tr0_offset - tt1->utc_offset; - tr++->type_index = tr0->type_index; - } - assert(tr == &transitions_[0] + transitions_.size()); + leap_year = !leap_year && IsLeap(last_year_ + 1); + } + + return true; } -bool TimeZoneInfo::Load(const std::string& name, ZoneInfoSource* zip) { +bool TimeZoneInfo::Load(ZoneInfoSource* zip) { // Read and validate the header. tzhead tzh; if (zip->Read(&tzh, sizeof(tzh)) != sizeof(tzh)) return false; @@ -430,7 +427,7 @@ bool TimeZoneInfo::Load(const std::string& name, ZoneInfoSource* zip) { const char* bp = tbuf.data(); // Decode and validate the transitions. - transitions_.reserve(hdr.timecnt + 2); // We might add a couple. + transitions_.reserve(hdr.timecnt + 2); transitions_.resize(hdr.timecnt); for (std::size_t i = 0; i != hdr.timecnt; ++i) { transitions_[i].unix_time = (time_len == 4) ? Decode32(bp) : Decode64(bp); @@ -449,6 +446,7 @@ bool TimeZoneInfo::Load(const std::string& name, ZoneInfoSource* zip) { } // Decode and validate the transition types. + transition_types_.reserve(hdr.typecnt + 2); transition_types_.resize(hdr.typecnt); for (std::size_t i = 0; i != hdr.typecnt; ++i) { transition_types_[i].utc_offset = @@ -475,6 +473,7 @@ bool TimeZoneInfo::Load(const std::string& name, ZoneInfoSource* zip) { } // Copy all the abbreviations. + abbreviations_.reserve(hdr.charcnt + 10); abbreviations_.assign(bp, hdr.charcnt); bp += hdr.charcnt; @@ -506,7 +505,7 @@ bool TimeZoneInfo::Load(const std::string& name, ZoneInfoSource* zip) { // If we did not find version information during the standard loading // process (as of tzh_version '3' that is unsupported), then ask the - // ZoneInfoSource for any out-of-bound version std::string it may be privy to. + // ZoneInfoSource for any out-of-bound version string it may be privy to. if (version_.empty()) { version_ = zip->Version(); } @@ -525,19 +524,29 @@ bool TimeZoneInfo::Load(const std::string& name, ZoneInfoSource* zip) { transitions_.resize(hdr.timecnt); // Ensure that there is always a transition in the first half of the - // time line (the second half is handled in ExtendTransitions()) so that - // the signed difference between a civil_second and the civil_second of - // its previous transition is always representable, without overflow. - // A contemporary zic will usually have already done this for us. + // time line (the second half is handled below) so that the signed + // difference between a civil_second and the civil_second of its + // previous transition is always representable, without overflow. if (transitions_.empty() || transitions_.front().unix_time >= 0) { Transition& tr(*transitions_.emplace(transitions_.begin())); - tr.unix_time = -(1LL << 59); // see tz/zic.c "BIG_BANG" + tr.unix_time = -(1LL << 59); // -18267312070-10-26T17:01:52+00:00 tr.type_index = default_transition_type_; - hdr.timecnt += 1; } // Extend the transitions using the future specification. - ExtendTransitions(name, hdr); + if (!ExtendTransitions()) return false; + + // Ensure that there is always a transition in the second half of the + // time line (the first half is handled above) so that the signed + // difference between a civil_second and the civil_second of its + // previous transition is always representable, without overflow. + const Transition& last(transitions_.back()); + if (last.unix_time < 0) { + const std::uint_fast8_t type_index = last.type_index; + Transition& tr(*transitions_.emplace(transitions_.end())); + tr.unix_time = 2147483647; // 2038-01-19T03:14:07+00:00 + tr.type_index = type_index; + } // Compute the local civil time for each transition and the preceding // second. These will be used for reverse conversions in MakeTime(). @@ -569,14 +578,17 @@ bool TimeZoneInfo::Load(const std::string& name, ZoneInfoSource* zip) { namespace { +using FilePtr = std::unique_ptr; + // fopen(3) adaptor. -inline FILE* FOpen(const char* path, const char* mode) { +inline FilePtr FOpen(const char* path, const char* mode) { #if defined(_MSC_VER) FILE* fp; if (fopen_s(&fp, path, mode) != 0) fp = nullptr; - return fp; + return FilePtr(fp, fclose); #else - return fopen(path, mode); // TODO: Enable the close-on-exec flag. + // TODO: Enable the close-on-exec flag. + return FilePtr(fopen(path, mode), fclose); #endif } @@ -604,11 +616,11 @@ class FileZoneInfoSource : public ZoneInfoSource { protected: explicit FileZoneInfoSource( - FILE* fp, std::size_t len = std::numeric_limits::max()) - : fp_(fp, fclose), len_(len) {} + FilePtr fp, std::size_t len = std::numeric_limits::max()) + : fp_(std::move(fp)), len_(len) {} private: - std::unique_ptr fp_; + FilePtr fp_; std::size_t len_; }; @@ -637,17 +649,9 @@ std::unique_ptr FileZoneInfoSource::Open( path.append(name, pos, std::string::npos); // Open the zoneinfo file. - FILE* fp = FOpen(path.c_str(), "rb"); + auto fp = FOpen(path.c_str(), "rb"); if (fp == nullptr) return nullptr; - std::size_t length = 0; - if (fseek(fp, 0, SEEK_END) == 0) { - long offset = ftell(fp); - if (offset >= 0) { - length = static_cast(offset); - } - rewind(fp); - } - return std::unique_ptr(new FileZoneInfoSource(fp, length)); + return std::unique_ptr(new FileZoneInfoSource(std::move(fp))); } class AndroidZoneInfoSource : public FileZoneInfoSource { @@ -656,8 +660,9 @@ class AndroidZoneInfoSource : public FileZoneInfoSource { std::string Version() const override { return version_; } private: - explicit AndroidZoneInfoSource(FILE* fp, std::size_t len, const char* vers) - : FileZoneInfoSource(fp, len), version_(vers) {} + explicit AndroidZoneInfoSource(FilePtr fp, std::size_t len, + std::string version) + : FileZoneInfoSource(std::move(fp), len), version_(std::move(version)) {} std::string version_; }; @@ -669,8 +674,8 @@ std::unique_ptr AndroidZoneInfoSource::Open( // See Android's libc/tzcode/bionic.cpp for additional information. for (const char* tzdata : {"/data/misc/zoneinfo/current/tzdata", "/system/usr/share/zoneinfo/tzdata"}) { - std::unique_ptr fp(FOpen(tzdata, "rb"), fclose); - if (fp.get() == nullptr) continue; + auto fp = FOpen(tzdata, "rb"); + if (fp == nullptr) continue; char hbuf[24]; // covers header.zonetab_offset too if (fread(hbuf, 1, sizeof(hbuf), fp.get()) != sizeof(hbuf)) continue; @@ -696,7 +701,7 @@ std::unique_ptr AndroidZoneInfoSource::Open( if (strcmp(name.c_str() + pos, ebuf) == 0) { if (fseek(fp.get(), static_cast(start), SEEK_SET) != 0) break; return std::unique_ptr(new AndroidZoneInfoSource( - fp.release(), static_cast(length), vers)); + std::move(fp), static_cast(length), vers)); } } } @@ -704,6 +709,69 @@ std::unique_ptr AndroidZoneInfoSource::Open( return nullptr; } +// A zoneinfo source for use inside Fuchsia components. This attempts to +// read zoneinfo files from one of several known paths in a component's +// incoming namespace. [Config data][1] is preferred, but package-specific +// resources are also supported. +// +// Fuchsia's implementation supports `FileZoneInfoSource::Version()`. +// +// [1]: +// https://fuchsia.dev/fuchsia-src/development/components/data#using_config_data_in_your_component +class FuchsiaZoneInfoSource : public FileZoneInfoSource { + public: + static std::unique_ptr Open(const std::string& name); + std::string Version() const override { return version_; } + + private: + explicit FuchsiaZoneInfoSource(FilePtr fp, std::string version) + : FileZoneInfoSource(std::move(fp)), version_(std::move(version)) {} + std::string version_; +}; + +std::unique_ptr FuchsiaZoneInfoSource::Open( + const std::string& name) { + // Use of the "file:" prefix is intended for testing purposes only. + const std::size_t pos = (name.compare(0, 5, "file:") == 0) ? 5 : 0; + + // Prefixes where a Fuchsia component might find zoneinfo files, + // in descending order of preference. + const auto kTzdataPrefixes = { + "/config/data/tzdata/", + "/pkg/data/tzdata/", + "/data/tzdata/", + }; + const auto kEmptyPrefix = {""}; + const bool name_absolute = (pos != name.size() && name[pos] == '/'); + const auto prefixes = name_absolute ? kEmptyPrefix : kTzdataPrefixes; + + // Fuchsia builds place zoneinfo files at "". + for (const std::string prefix : prefixes) { + std::string path = prefix; + if (!prefix.empty()) path += "zoneinfo/tzif2/"; // format + path.append(name, pos, std::string::npos); + + auto fp = FOpen(path.c_str(), "rb"); + if (fp == nullptr) continue; + + std::string version; + if (!prefix.empty()) { + // Fuchsia builds place the version in "revision.txt". + std::ifstream version_stream(prefix + "revision.txt"); + if (version_stream.is_open()) { + // revision.txt should contain no newlines, but to be + // defensive we read just the first line. + std::getline(version_stream, version); + } + } + + return std::unique_ptr( + new FuchsiaZoneInfoSource(std::move(fp), std::move(version))); + } + + return nullptr; +} + } // namespace bool TimeZoneInfo::Load(const std::string& name) { @@ -718,12 +786,13 @@ bool TimeZoneInfo::Load(const std::string& name) { // Find and use a ZoneInfoSource to load the named zone. auto zip = cctz_extension::zone_info_source_factory( - name, [](const std::string& name) -> std::unique_ptr { - if (auto zip = FileZoneInfoSource::Open(name)) return zip; - if (auto zip = AndroidZoneInfoSource::Open(name)) return zip; + name, [](const std::string& n) -> std::unique_ptr { + if (auto z = FileZoneInfoSource::Open(n)) return z; + if (auto z = AndroidZoneInfoSource::Open(n)) return z; + if (auto z = FuchsiaZoneInfoSource::Open(n)) return z; return nullptr; }); - return zip != nullptr && Load(name, zip.get()); + return zip != nullptr && Load(zip.get()); } // BreakTime() translation for a particular transition type. @@ -897,8 +966,8 @@ bool TimeZoneInfo::NextTransition(const time_point& tp, const Transition* begin = &transitions_[0]; const Transition* end = begin + transitions_.size(); if (begin->unix_time <= -(1LL << 59)) { - // Do not report the BIG_BANG found in recent zoneinfo data as it is - // really a sentinel, not a transition. See tz/zic.c. + // Do not report the BIG_BANG found in some zoneinfo data as it is + // really a sentinel, not a transition. See pre-2018f tz/zic.c. ++begin; } std::int_fast64_t unix_time = ToUnixSeconds(tp); @@ -923,8 +992,8 @@ bool TimeZoneInfo::PrevTransition(const time_point& tp, const Transition* begin = &transitions_[0]; const Transition* end = begin + transitions_.size(); if (begin->unix_time <= -(1LL << 59)) { - // Do not report the BIG_BANG found in recent zoneinfo data as it is - // really a sentinel, not a transition. See tz/zic.c. + // Do not report the BIG_BANG found in some zoneinfo data as it is + // really a sentinel, not a transition. See pre-2018f tz/zic.c. ++begin; } std::int_fast64_t unix_time = ToUnixSeconds(tp); -- cgit v1.2.3