tree e916dba00a9c6b550845dcfa2d2a927bb242d950
parent b54da87ee10f1ffee942f5896774d72bd656e594
author Youssef Elghareeb <ghareeb@google.com> 1626869227 +0200
committer Youssef Elghareeb <ghareeb@google.com> 1626947184 +0200

Adjust FileInfoJson to accept 1-based integers for parent

There was a discrepancy between parent representations in DiffOperations
and FileInfoJson: The former used to accept 1-based parents, while the
latter accepted 0-based parents. There was a programming bug in
FilesInCommitCollection, since this API accepts a value "0" for parent
to indicate the default or auto-merge commit (See documentation in [1]).
The bug happened because we passed `parent - 1` (=-1) to FileInfoJson
resulting in array out of bounds while resolving the parent commit.

In this change we fix this bug. We unify the parent representation in
DiffOperations and FileInfoJson such that they both accept a 1-based
representation for parents. Also adding javadoc to clarify this. We also
remove the @Nullable from DiffOperations and use a primitive integer
with 0 to represent the default/auto-merge. We update all callers to
pass 0 instead of null.

[1]
https://gerrit-review.googlesource.com/Documentation/rest-api-projects.html#list-files

Change-Id: Ic10d6e925b2b0e1db295997f5e28c10a085874a9