tree 5d38fd08e28d78b2a16cca37dc41bae87d22548d
parent 6117cd3cd25b84ac530e142a3db026168424bd72
author Patrick Hiesel <hiesel@google.com> 1626869978 +0200
committer Patrick Hiesel <hiesel@google.com> 1627548920 +0200

LabelTypes: Return an Optional to make clear that value can be absent

When asking LabelTypes for a LabelType by name or ID, that LabelType
is only returned if the project has a label with name or ID
configured.

Most places in Gerrit correctly handled this implicit behavior, but
new code for SubmitRequirements (ChangeField:getMaxMinAnyLabels) did
not which made it fail with a NullPointerException in case a label
that was voted on the change was removed from project.config
since the vote was granted.

In this commit, we fix the NPE by reworking LabelTypes to return
an Optional which also makes it so that this programmer error
can't occur in the future.

Change-Id: I9e0f3a940ce21ef1e46b3dbb1675267ae1d76459