NXD Add support for apply patch in Merge request

If there is only 1 commit is present in MR, apply patch buttun is enabled
allow to merge the MR in a single commit.

app/assets/javascripts/vue_merge_request_widget/components/states/ready_to_merge.vue

@@ -173,6 +173,13 @@ export default {
 
       return this.mr.commitsCount;
     },
+    ApplyPatchButtonText() {
+
+      return __('Apply Patch ');
+    },
+    isApplyPatchAllowed() {
+      return this.mr.commitsCount !== 1 || this.isMergeButtonDisabled;
+    },
     preferredAutoMergeStrategy() {
       if (this.glFeatures.mergeRequestWidgetGraphql) {
         return MergeRequestStore.getPreferredAutoMergeStrategy(
@@ -329,7 +336,7 @@ export default {
         : this.mr.commitMessageWithDescription;
       this.commitMessage = includeDescription ? commitMessageWithDescription : commitMessage;
     },
-    handleMergeButtonClick(useAutoMerge, mergeImmediately = false) {
+    handleMergeButtonClick(useAutoMerge, mergeImmediately = false, apply_patch = false) {
       if (mergeImmediately) {
         this.isMergingImmediately = true;
       }
@@ -343,6 +350,7 @@ export default {
         auto_merge_strategy: useAutoMerge ? this.preferredAutoMergeStrategy : undefined,
         should_remove_source_branch: this.removeSourceBranch === true,
         squash: this.squashBeforeMerge,
+        apply_patch: apply_patch,
       };
 
       // If users can't alter the squash message (e.g. for 1-commit merge requests),
@@ -525,6 +533,18 @@ export default {
                   @mergeImmediately="onMergeImmediatelyConfirmation"
                 />
               </gl-dropdown>
+              <gl-button
+                size="medium"
+                category="primary"
+                class="accept-merge-request"
+                data-testid="apply-button"
+                :variant="mergeButtonVariant"
+                :disabled="isApplyPatchAllowed"
+                :loading="isMakingRequest"
+                data-qa-selector="apply_patch_button"
+                @click="handleMergeButtonClick(false, false, true)"
+                >{{ ApplyPatchButtonText }}</gl-button
+              >
             </gl-button-group>
             <div
               v-if="shouldShowMergeControls"

app/controllers/projects/merge_requests_controller.rb

@@ -374,7 +374,7 @@ class Projects::MergeRequestsController < Projects::MergeRequests::ApplicationCo
   end
 
   def merge_params
-    params.permit(merge_params_attributes)
+    params.permit(merge_params_attributes, :apply_patches)
   end
 
   def merge_params_attributes

app/models/merge_request.rb

@@ -1311,7 +1311,8 @@ class MergeRequest < ApplicationRecord
     end
 
     message << "#{description}" if include_description && description.present?
-    message << "See merge request #{to_reference(full: true)}"
+    #message << "See merge request #{to_reference(full: true)}"
+    message << "/reviewed-on #{Gitlab::UrlBuilder.build(self)}"
 
     message.join("\n\n")
   end

app/services/merge_requests/merge_service.rb

@@ -84,7 +84,15 @@ module MergeRequests
 
     def commit
       log_info("Git merge started on JID #{merge_jid}")
-      commit_id = try_merge
+
+      mr_1patch = merge_request.commits.size == 1
+      do_apply = params[:apply_patches] || mr_1patch
+      do_merge = !do_apply
+      patch = merge_request.commits.reverse.first
+
+      commit_id = do_merge ? try_merge \
+          : repository.cherry_pick(current_user, repository.commit(patch.sha), merge_request.target_branch, commit_message,
+            start_branch_name: nil, start_project: project, dry_run: false)
 
       if commit_id
         log_info("Git merge finished on JID #{merge_jid} commit #{commit_id}")
@@ -99,7 +107,7 @@ module MergeRequests
 
     def try_merge
       repository.merge(current_user, source, merge_request, commit_message).tap do
-        merge_request.update_column(:squash_commit_sha, source) if merge_request.squash_on_merge?
+        merge_request.update_column(:squashoptions_commit_sha, source) if merge_request.squash_on_merge?
       end
     rescue Gitlab::Git::PreReceiveError => e
       raise MergeError,

app/views/shared/_commit_message_container.html.haml

@@ -2,7 +2,7 @@
   - nonce = SecureRandom.hex
   - descriptions = local_assigns.slice(:message_with_description, :message_without_description)
   = label_tag "commit_message-#{nonce}", class: 'col-form-label col-sm-2' do
-    #{ _('Commit message') }
+    local_assigns[:label_text] || #{ _('Commit message') }
   .col-sm-10
     .commit-message-container
       .max-width-marker

qa/qa/page/merge_request/show.rb

@@ -73,6 +73,7 @@ module QA
 
         view 'app/assets/javascripts/vue_merge_request_widget/components/states/ready_to_merge.vue' do
           element :merge_button
+          element :apply_patch_button
           element :fast_forward_message_content
           element :merge_moment_dropdown
           element :merge_immediately_menu_item
@@ -255,10 +256,12 @@ module QA
         # Waits up 60 seconds and raises an error if unable to merge
         def wait_until_ready_to_merge
           has_element?(:merge_button)
+          has_element?(:apply_patch_button)
 
           # The merge button is enabled via JS
           wait_until(reload: false) do
             !find_element(:merge_button).disabled?
+            !find_element(:apply_patch_button).disabled?
           end
         end
 

[Alain Takoudjou]

@tomo @jerome @kirr This commit is adding apply patch button for MR with 1 commit.

As we discussed with @tomo, I'm going to enable it for MR with more than one commits and it will do Fast Forward Merge, by calling https://lab.nexedi.com/nexedi/gitlab-ce/-/blob/v13.12.15-nxd/lib/gitlab/git/repository.rb#L614. It's not possible with ff_merge to update commit message, gitlab add a link to the MR in the commit page (see this one: slapos@9227dd59).

[Kirill Smelkov]

@alain.takoudjou, @tomo, thanks for heads up and for bringing "Apply patch" back. It is really good to see.

I have one suggestion: for multipatch case instead of going through fast-forward merge, we could loop through all patches in the merge-request and cherry-pick them one by one like we already do for single-patch case. Then adding /reviewed-on ... line to each patch should be relatively straightforward.

Thanks, once again, for reviwing the "apply patch" story.
Kirill

[Alain Takoudjou]

for multipatch case instead of going through fast-forward merge, we could loop through all patches in the merge-request and cherry-pick them one by one ...

Yes maybe better because ff need rebase, @tomo ?