public inbox for libstdc++-cvs@sourceware.org help / color / mirror / Atom feed
From: Jonathan Wakely <redi@gcc.gnu.org> To: gcc-cvs@gcc.gnu.org, libstdc++-cvs@gcc.gnu.org Subject: [gcc r13-5387] libstdc++: Add workaround for old tzdata.zi files Date: Thu, 26 Jan 2023 13:50:19 +0000 (GMT) [thread overview] Message-ID: <20230126135019.CB4B23858D28@sourceware.org> (raw) https://gcc.gnu.org/g:2e445d9e99814644e7edabac4c3feb5df50303d9 commit r13-5387-g2e445d9e99814644e7edabac4c3feb5df50303d9 Author: Jonathan Wakely <jwakely@redhat.com> Date: Thu Jan 26 11:35:00 2023 +0000 libstdc++: Add workaround for old tzdata.zi files The tzdata.zi file in the RHEL 6 tzdata-2018e-3.el6 package (with version "unknown") does not conform to the current rules described in the zic(8) man page. Specifically, a Rule name must not start with the character '+' in the current rules, but the older tzdata.zi file used "+" as the name of rules for the "Europe/Sofia" zone. Add a special case to the logic that detects whether a RULES field refers to a named rule or is an offset from standard time. For a string matching exactly "+" treat it as a named Rule, but for any other string starting with '+' treat it as an offset. libstdc++-v3/ChangeLog: * src/c++20/tzdb.cc (operator>>(istream&, ZoneInfo&)): Allow rules named "+" for compatibility with older tzdata.zi files. Diff: --- libstdc++-v3/src/c++20/tzdb.cc | 49 +++++++++++++++++++++++++++++------------- 1 file changed, 34 insertions(+), 15 deletions(-) diff --git a/libstdc++-v3/src/c++20/tzdb.cc b/libstdc++-v3/src/c++20/tzdb.cc index c945f002ad7..c956e861891 100644 --- a/libstdc++-v3/src/c++20/tzdb.cc +++ b/libstdc++-v3/src/c++20/tzdb.cc @@ -1967,6 +1967,22 @@ namespace std::chrono return in; } + // Test whether the RULES field of a Zone line is a valid Rule name. + inline bool + is_rule_name(string_view rules) noexcept + { + // The NAME field of a Rule line must start with a character that is + // neither an ASCII digit nor '-' nor '+'. + if (('0' <= rules[0] && rules[0] <= '9') || rules[0] == '-') + return false; + // However, some older tzdata.zi files (e.g. in tzdata-2018e-3.el6 RPM) + // used "+" as a Rule name, so we need to handle that special case. + if (rules[0] == '+') + return rules.size() == 1; // "+" is a rule name, "+1" is not. + // Everything else is the name of a Rule. + return true; + } + istream& operator>>(istream& in, ZoneInfo& inf) { // STDOFF RULES FORMAT [UNTIL] @@ -1976,25 +1992,28 @@ namespace std::chrono in >> off >> quoted{rules} >> fmt; inf.m_offset = off.time; - if (rules == "-") - { - // Standard time always applies, no DST. - inf.set_abbrev(fmt); - } - else if (string_view("0123456789-+").find(rules[0]) != string_view::npos) + if (is_rule_name(rules)) { - // rules specifies the difference from standard time. - at_time rules_time; - istringstream in2(std::move(rules)); - in2 >> rules_time; - inf.m_save = duration_cast<minutes>(rules_time.time); - select_std_or_dst_abbrev(fmt, inf.m_save); - inf.set_abbrev(fmt); + // `rules` refers to a named Rule which describes transitions. + inf.set_rules_and_format(rules, fmt); } else { - // rules refers to a named Rule which describes transitions. - inf.set_rules_and_format(rules, fmt); + if (rules == "-") + { + // Standard time always applies, no DST. + } + else + { + // `rules` specifies the difference from standard time, + // e.g., "-2:30" + at_time rules_time; + istringstream in2(std::move(rules)); + in2 >> rules_time; + inf.m_save = duration_cast<minutes>(rules_time.time); + select_std_or_dst_abbrev(fmt, inf.m_save); + } + inf.set_abbrev(fmt); } // YEAR [MONTH [DAY [TIME]]]
reply other threads:[~2023-01-26 13:50 UTC|newest] Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20230126135019.CB4B23858D28@sourceware.org \ --to=redi@gcc.gnu.org \ --cc=gcc-cvs@gcc.gnu.org \ --cc=libstdc++-cvs@gcc.gnu.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).