Default DateTime parser format is stricter than previous versions, causing incompatibility

[jamesmcmillan]

In this commit, for DateTimeSerializer:
cf2f4c2#diff-86756f80e06fe3b0a847c963534b14baR55

DateTime.parse() is replaced by using the JacksonJodaDateFormat, which defaults to FormatConfig.DEFAULT_DATETIME_FORMAT, which is defined as new JacksonJodaDateFormat(ISODateTimeFormat.dateTime().withZoneUTC()).

DateTime.parse() uses ISODateTimeFormat.dateTimeParser().withOffsetParsed():
http://www.joda.org/joda-time/apidocs/org/joda/time/DateTime.html#parse-java.lang.String-

So ultimately, the default date time parser format has changed from ISODateTimeFormat.dateTimeParser() to ISODateTimeFormat.dateTime(). Although similar, ISODateTimeFormat.dateTimeParser() is much less restrictive:
http://www.joda.org/joda-time/apidocs/org/joda/time/format/ISODateTimeFormat.html#dateTime--
http://www.joda.org/joda-time/apidocs/org/joda/time/format/ISODateTimeFormat.html#dateTimeParser--

As an example, the datetime "2015-07-27T08:11:07-07:00" is missing the .SSS milliseconds value, so it fails in 2.6.0 but works in 2.5.4:

Caused by: java.lang.IllegalArgumentException: Invalid format: "2015-07-27T08:11:07-07:00" is malformed at "-07:00"
    at org.joda.time.format.DateTimeFormatter.parseDateTime(DateTimeFormatter.java:899) ~[joda-time-2.8.1.jar:2.8.1]
    at com.fasterxml.jackson.datatype.joda.deser.DateTimeDeserializer.deserialize(DateTimeDeserializer.java:90) ~[jackson-datatype-joda-2.6.0.jar:2.6.0]
    at com.fasterxml.jackson.datatype.joda.deser.DateTimeDeserializer.deserialize(DateTimeDeserializer.java:22) ~[jackson-datatype-joda-2.6.0.jar:2.6.0]
    at com.fasterxml.jackson.databind.deser.SettableBeanProperty.deserialize(SettableBeanProperty.java:520) ~[jackson-databind-2.6.0.jar:2.6.0]
    at com.fasterxml.jackson.databind.deser.impl.FieldProperty.deserializeAndSet(FieldProperty.java:101) ~[jackson-databind-2.6.0.jar:2.6.0]
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:256) ~[jackson-databind-2.6.0.jar:2.6.0]

A workaround in this situation is to add a @JsonFormat annotation to the property specifying the specific format, e.g: @JsonFormat(pattern="yyyy-MM-dd'T'HH:mm:ssZZ")

[cowtowncoder]

Ugh. I am surprised to find that said underlying change actually changes behavior, so change was definitely not intentional. I thought I had looked briefly at patterns to make sure they fit with expected ones, but I think I was assuming that if names (of constants) matched, underlying patterns would too.

Should be fixed for 2.6.1.