Merge branch 'fix-deployment-creation-on-build-retry' into 'master'

Fix creation of deployment on build that is retried, redeployed or rollback

## What does this MR do?
Add missing `environment` to be copied when retrying a build.

## Why was this MR needed?
The retried builds did not create a deployments.

## What are the relevant issue numbers?
Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/19521

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

See merge request !5275

CHANGELOG

@@ -61,6 +61,7 @@ v 8.10.0 (unreleased)
   - Allow expanding and collapsing files in diff view (!4990)
   - Collapse large diffs by default (!4990)
   - Fix mentioned users list on diff notes
+  - Fix creation of deployment on build that is retried, redeployed or rollback
   - Check for conflicts with existing Project's wiki path when creating a new project.
   - Show last push widget in upstream after push to fork
   - Fix stage status shown for pipelines

app/models/ci/build.rb

@@ -53,6 +53,7 @@ module Ci
         new_build.stage_idx = build.stage_idx
         new_build.trigger_request = build.trigger_request
         new_build.user = user
+        new_build.environment = build.environment
         new_build.save
         MergeRequests::AddTodoWhenBuildFailsService.new(build.project, nil).close(new_build)
         new_build

spec/services/create_deployment_service_spec.rb

@@ -89,6 +89,12 @@ describe CreateDeploymentService, services: true do
         expect_any_instance_of(described_class).to receive(:execute)
         subject
       end
+
+      it 'is set as deployable' do
+        subject
+
+        expect(Deployment.last.deployable).to eq(deployable)
+      end
     end
 
     context 'without environment specified' do
@@ -105,6 +111,8 @@ describe CreateDeploymentService, services: true do
 
       context 'when build succeeds' do
         it_behaves_like 'does create environment and deployment' do
+          let(:deployable) { build }
+
           subject { build.success }
         end
       end
@@ -114,6 +122,14 @@ describe CreateDeploymentService, services: true do
           subject { build.drop }
         end
       end
+
+      context 'when build is retried' do
+        it_behaves_like 'does create environment and deployment' do
+          let(:deployable) { Ci::Build.retry(build) }
+
+          subject { deployable.success }
+        end
+      end
     end
   end
 end