tree cddf0edfa2f31ca7f72b12e5dfb845583f5b26c1
parent f648782f5fa7f04ea9f6b82885ea055e65196a19
author Daniel Kurka <dankurka@google.com> 1465837593 +0200
committer Daniel Kurka <dankurka@google.com> 1465837593 +0200

Add critical checks in StringJoiner.

This is a stop gap measure to make tests pass.
As a follow up compiler needs to be fixed to handle
CharSequence.toString properly for null values.

Change-Id: I0b9a50c762b16f9dae0693171bb135bedeb26ff7