elasticsearch/elasticsearch — pull request #5929 by bleskes (2014-04-24 11:02:12+00:00)
Title: Version types `EXTERNAL` & `EXTERNAL_GTE` test for version equality in read operation & disallow them in the Update API

Separate version check logic for reads and writes for all version types, which allows different behavior in these cases.
Change `VersionType.EXTERNAL` & `VersionType.EXTERNAL_GTE` to behave the same as `VersionType.INTERNAL` for read operations.
The previous behavior was fit for writes but is useless in reads.

This commit also makes the usage of `EXTERNAL` & `EXTERNAL_GTE` in the update api raise a validation error as it make cause data to
be lost.

Closes #5663 , closes #5661