From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2181) id CB4B23858D28; Thu, 26 Jan 2023 13:50:19 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org CB4B23858D28 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1674741019; bh=s7oZW0E3TzgcYHpwJBqzNyG4cJu+IJNC1XVTnz8V0zQ=; h=From:To:Subject:Date:From; b=nsVRpOca500WcgR0sP8+fwnhxjnkbX+DMSLEi1LzD07n4fCcqkwjZrMnPlR8HqZof ILjdWIGkI9zKiumyUKiWx6Zt8med2J5k53ldCgJU0dA/RrQXS4u5qakv4znORCWyJ3 W8842WWZNf2cWCK6Fkz8PYIok1y5eygC+XmI1Bbo= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Jonathan Wakely To: gcc-cvs@gcc.gnu.org, libstdc++-cvs@gcc.gnu.org Subject: [gcc r13-5387] libstdc++: Add workaround for old tzdata.zi files X-Act-Checkin: gcc X-Git-Author: Jonathan Wakely X-Git-Refname: refs/heads/master X-Git-Oldrev: 3376467ce090aa0966d59ca3aea35db4f17a4b47 X-Git-Newrev: 2e445d9e99814644e7edabac4c3feb5df50303d9 Message-Id: <20230126135019.CB4B23858D28@sourceware.org> Date: Thu, 26 Jan 2023 13:50:19 +0000 (GMT) List-Id: https://gcc.gnu.org/g:2e445d9e99814644e7edabac4c3feb5df50303d9 commit r13-5387-g2e445d9e99814644e7edabac4c3feb5df50303d9 Author: Jonathan Wakely 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(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(rules_time.time); + select_std_or_dst_abbrev(fmt, inf.m_save); + } + inf.set_abbrev(fmt); } // YEAR [MONTH [DAY [TIME]]]