In certain cases Time#zone and Time#strftime("%Z") might not match, causing "returns the timezone with %Z" in spec/ruby/core/time/strftime_spec.rb to fail.

How to reproduce

One of such cases happens when running joda-time <= 2.8.0 and OpenJDK 8u60 or earlier.

Due to a change in OpenJDK 8u60, Java's DateTimeUtils.getZoneStrings() is now returning 7 elements instead of just 5, causing joda-time DefaultNameFormatter.getName() to return null. In effect causing joda-time DateTimeZone.getShortName() or DateTimeZone.getName() to return TZ in [+-]hh:mm format instead of the abbreviation name. The issue was reported in JodaOrg/joda-time#288 and JodaOrg/joda-time#291.

To reproduce simply run:

$ JAVA_HOME=<jdk8u60 home> ./bin/jruby spec/mspec/bin/mspec run spec/ruby/core/time/strftime_spec.rb

with joda-time <= 2.8.0.

Current result:

Requires OpenJDK 8u60 (or earlier) and joda-time <= 2.8.0.

Time.strftime("%Z") returns the TZ in_"[+-]hh:mm_ format (as if "%z" was given), while Time.zone returns the TZ abbreviation name.

$ ./bin/jruby spec/mspec/bin/mspec run spec/ruby/core/time/strftime_spec.rb 
jruby 1.7.21 (1.9.3p551) 2015-09-01 fffffff on OpenJDK 64-Bit Server VM 1.8.0_66-internal-b01 +jit [linux-amd64]

1)
Time#strftime returns the timezone with %Z FAILED
Expected "-03:00"
 to equal "BRT"

/build/jruby-shb6eX/jruby-1.7.21/spec/ruby/core/time/strftime_spec.rb:238:in `(root)'
org/jruby/RubyBasicObject.java:1574:in `instance_eval'
org/jruby/RubyEnumerable.java:1412:in `all?'
org/jruby/RubyFixnum.java:275:in `times'
org/jruby/RubyArray.java:1613:in `each'
/build/jruby-shb6eX/jruby-1.7.21/spec/ruby/core/time/strftime_spec.rb:4:in `(root)'
org/jruby/RubyKernel.java:1059:in `load'
org/jruby/RubyBasicObject.java:1574:in `instance_eval'
org/jruby/RubyArray.java:1613:in `each'

Expected result:

The spec states that Time#zone and Time#strftime("%Z") should always match. Also, Time.strftime documentation states that %Z - Time zone abbreviation name.

Background, why Time#zone and Time#strftime differs

JRuby's Time#zone has additional code to be able to handle a [+-]hh:mm return by DateTimeZone.getShortName() when compared to Time#strftime("%Z").

RubyTime.zone() [890-908]

        String zone = dt.getZone().getShortName(dt.getMillis());

        Matcher offsetMatcher = TIME_OFFSET_PATTERN.matcher(zone);

        if (offsetMatcher.matches()) {
            boolean minus_p = offsetMatcher.group(1).toString().equals("-");
            int hourOffset  = Integer.valueOf(offsetMatcher.group(2));

            if (zone.equals("+00:00")) {
                zone = "GMT";
            } else {
                // try non-localized time zone name
                zone = dt.getZone().getNameKey(dt.getMillis());
                if (zone == null) {
                    char sign = minus_p ? '+' : '-';
                    zone = "GMT" + sign + hourOffset;
                }
            }
        }

RubyDateFormatter.format() [489-491] and
RubyDateFormat.format() [622-624]

                case FORMAT_ZONE_ID:
                    output = dt.getZone().getShortName(dt.getMillis());
                    break;

Some code from RubyTime.zone() offsetMatcher should be refactored (or copied) into RubyDateFormatter.format() and RubyDateFormat.format() FORMAT_ZONE_ID clauses.