Move identical merged branch check to merged_branch_names

app/models/repository.rb

@@ -916,19 +916,13 @@ class Repository
     end
   end
 
-  def merged_to_root_ref?(branch_or_name, pre_loaded_merged_branches = nil)
+  def merged_to_root_ref?(branch_or_name)
     branch = Gitlab::Git::Branch.find(self, branch_or_name)
 
     if branch
       @root_ref_sha ||= commit(root_ref).sha
       same_head = branch.target == @root_ref_sha
-      merged =
-        if pre_loaded_merged_branches
-          pre_loaded_merged_branches.include?(branch.name)
-        else
-          ancestor?(branch.target, @root_ref_sha)
-        end
-
+      merged = ancestor?(branch.target, @root_ref_sha)
       !same_head && merged
     else
       nil

app/views/projects/branches/index.html.haml

@@ -41,7 +41,7 @@
   - if @branches.any?
     %ul.content-list.all-branches
       - @branches.each do |branch|
-        = render "projects/branches/branch", branch: branch, merged: @repository.merged_to_root_ref?(branch, @merged_branch_names)
+        = render "projects/branches/branch", branch: branch, merged: @merged_branch_names.include?(branch.name)
     = paginate @branches, theme: 'gitlab'
   - else
     .nothing-here-block

lib/api/entities.rb

@@ -271,7 +271,11 @@ module API
       end
 
       expose :merged do |repo_branch, options|
-        options[:project].repository.merged_to_root_ref?(repo_branch, options[:merged_branch_names])
+        if options[:merged_branch_names]
+          options[:merged_branch_names].include?(repo_branch.name)
+        else
+          options[:project].repository.merged_to_root_ref?(repo_branch)
+        end
       end
 
       expose :protected do |repo_branch, options|

lib/gitlab/git/repository.rb

@@ -1222,11 +1222,21 @@ module Gitlab
         sort_branches(branches, sort_by)
       end
 
+      # Gitaly migration: https://gitlab.com/gitlab-org/gitaly/issues/695
       def git_merged_branch_names(branch_names = [])
-        lines = run_git(['branch', '--merged', root_ref] + branch_names)
-          .first.lines
+        root_sha = find_branch(root_ref).target
 
-        lines.map(&:strip)
+        git_arguments =
+          %W[branch --merged #{root_sha}
+             --format=%(refname:short)\ %(objectname)] + branch_names
+
+        lines = run_git(git_arguments).first.lines
+
+        lines.each_with_object([]) do |line, branches|
+          name, sha = line.strip.split(' ', 2)
+
+          branches << name if sha != root_sha
+        end
       end
 
       def log_using_shell?(options)

spec/lib/gitlab/git/repository_spec.rb

@@ -1211,12 +1211,17 @@ describe Gitlab::Git::Repository, seed_helper: true do
     end
 
     context 'when no branch names are specified' do
-      it 'returns all merged branch names' do
+      before do
+        repository.create_branch('identical', 'master')
+      end
+
+      it 'returns all merged branch names except for identical one' do
         names = repository.merged_branch_names
 
         expect(names).to include('merge-test')
         expect(names).to include('fix-mode')
         expect(names).not_to include('feature')
+        expect(names).not_to include('identical')
       end
     end
   end

spec/models/repository_spec.rb

@@ -299,24 +299,6 @@ describe Repository do
 
       it { is_expected.to be_falsey }
     end
-
-    context 'when pre-loaded merged branches are provided' do
-      using RSpec::Parameterized::TableSyntax
-
-      where(:branch, :pre_loaded, :expected) do
-        'not-merged-branch' | ['branch-merged']     | false
-        'branch-merged'     | ['not-merged-branch'] | false
-        'branch-merged'     | ['branch-merged']     | true
-        'not-merged-branch' | ['not-merged-branch'] | false
-        'master'            | ['master']            | false
-      end
-
-      with_them do
-        subject { repository.merged_to_root_ref?(branch, pre_loaded) }
-
-        it { is_expected.to eq(expected) }
-      end
-    end
   end
 
   describe '#can_be_merged?' do