Merge branch 'fix/builds-api-nil-commit' into 'master'

Fix builds API response that did not include commit data

## What does this MR do?

This is fix for problem with builds API response not including information about commit this build is created for.

## What are the relevant issue numbers?

Closes #18476 

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] API support added
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !4827

1 files changed, 1 insertions, 5 deletions

diff --git a/lib/api/entities.rb b/lib/api/entities.rb
index 2e397643ed1..2e6dfd7727f 100644
--- a/lib/api/entities.rb
+++ b/lib/api/entities.rb
@@ -444,11 +444,7 @@ module API
       expose :created_at, :started_at, :finished_at
       expose :user, with: User
       expose :artifacts_file, using: BuildArtifactFile, if: -> (build, opts) { build.artifacts? }
-      expose :commit, with: RepoCommit do |repo_obj, _options|
-        if repo_obj.respond_to?(:commit)
-          repo_obj.commit.commit_data
-        end
-      end
+      expose :commit, with: RepoCommit
       expose :runner, with: Runner
     end