[jira] [Created] (IO-689) All new FileUtils method with Java 8 time break on DST change

["Uwe Schindler (Jira)" <ji...@apache.org>]

Uwe Schindler created IO-689:
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             Summary: All new FileUtils method with Java 8 time break on DST change
                 Key: IO-689
                 URL: https://issues.apache.org/jira/browse/IO-689
             Project: Commons IO
          Issue Type: Task
          Components: Utilities
    Affects Versions: 2.8.0
            Reporter: Uwe Schindler


This commit in PR #124 breaks FileUtils with new Java 8 datetime APIs:
https://github.com/apache/commons-io/pull/124/commits/2eb549873470844c88681e92c64631f796002020

Because of this I had to put all of the methods to the list of blacklisted APIs in Apache Lucene / Solr. The reason for this change is that now all depend on local datetime, there's no way to pass an Instant with a UNIX timestamp through the API without it being corrupted due to forwards/backwards transformation.

Background: During DST changes the same local date time exists two times (in autumn, you have in most countries two time the 2:30am time, once before and once after the DST change - because time is rolled back).

With the above commit you first convert an Instant (which is by definition just a UNIX timestamp and can be converted as-is to a long) to a local Datetime and then back to an Instant. By this forward/backward transformation you get off by an hour during that one hour in autumn, when DST switches back to standard time.

Please revert this commit and release a bugfix.

There is no reason to convert an Instant to local and back, the arguments in the PR are plain wrong. Instants are timezoneless and are identical to UNIX timestamps.



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