Merge branch '9-2-stable-fix-conflicts-for-mr-11298' into '9-2-stable'

Fix 9.2 conflicts for "Fix conflict resolution from corrupted upstream"

See merge request !11533

7 files changed, 116 insertions, 102 deletions

diff --git a/app/controllers/projects/merge_requests_controller.rb b/app/controllers/projects/merge_requests_controller.rb
index 207fbad7856..b99ccd453b8 100755
--- a/app/controllers/projects/merge_requests_controller.rb
+++ b/app/controllers/projects/merge_requests_controller.rb
@@ -155,8 +155,8 @@ class Projects::MergeRequestsController < Projects::ApplicationController
       format.html { define_discussion_vars }
 
       format.json do
-        if @merge_request.conflicts_can_be_resolved_in_ui?
-          render json: @merge_request.conflicts
+        if @conflicts_list.can_be_resolved_in_ui?
+          render json: @conflicts_list
         elsif @merge_request.can_be_merged?
           render json: {
             message: 'The merge conflicts for this merge request have already been resolved. Please return to the merge request.',
@@ -173,9 +173,9 @@ class Projects::MergeRequestsController < Projects::ApplicationController
   end
 
   def conflict_for_path
-    return render_404 unless @merge_request.conflicts_can_be_resolved_in_ui?
+    return render_404 unless @conflicts_list.can_be_resolved_in_ui?
 
-    file = @merge_request.conflicts.file_for_path(params[:old_path], params[:new_path])
+    file = @conflicts_list.file_for_path(params[:old_path], params[:new_path])
 
     return render_404 unless file
 
@@ -183,7 +183,7 @@ class Projects::MergeRequestsController < Projects::ApplicationController
   end
 
   def resolve_conflicts
-    return render_404 unless @merge_request.conflicts_can_be_resolved_in_ui?
+    return render_404 unless @conflicts_list.can_be_resolved_in_ui?
 
     if @merge_request.can_be_merged?
       render status: :bad_request, json: { message: 'The merge conflicts for this merge request have already been resolved.' }
@@ -191,7 +191,9 @@ class Projects::MergeRequestsController < Projects::ApplicationController
     end
 
     begin
-      MergeRequests::ResolveService.new(@merge_request.source_project, current_user, params).execute(@merge_request)
+      MergeRequests::Conflicts::ResolveService.
+        new(merge_request).
+        execute(current_user, params)
 
       flash[:notice] = 'All merge conflicts were resolved. The merge request can now be merged.'
 
@@ -459,7 +461,9 @@ class Projects::MergeRequestsController < Projects::ApplicationController
   end
 
   def authorize_can_resolve_conflicts!
-    return render_404 unless @merge_request.conflicts_can_be_resolved_by?(current_user)
+    @conflicts_list = MergeRequests::Conflicts::ListService.new(@merge_request)
+
+    return render_404 unless @conflicts_list.can_be_resolved_by?(current_user)
   end
 
   def module_enabled
diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index e13e795dbed..2f3e4bf894a 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -897,35 +897,6 @@ class MergeRequest < ActiveRecord::Base
     project.repository.keep_around(self.merge_commit_sha)
   end
 
-  def conflicts
-    @conflicts ||= Gitlab::Conflict::FileCollection.new(self)
-  end
-
-  def conflicts_can_be_resolved_by?(user)
-    return false unless source_project
-
-    access = ::Gitlab::UserAccess.new(user, project: source_project)
-    access.can_push_to_branch?(source_branch)
-  end
-
-  def conflicts_can_be_resolved_in_ui?
-    return @conflicts_can_be_resolved_in_ui if defined?(@conflicts_can_be_resolved_in_ui)
-
-    return @conflicts_can_be_resolved_in_ui = false unless cannot_be_merged?
-    return @conflicts_can_be_resolved_in_ui = false unless has_complete_diff_refs?
-    return @conflicts_can_be_resolved_in_ui = false if branch_missing?
-
-    begin
-      # Try to parse each conflict. If the MR's mergeable status hasn't been updated,
-      # ensure that we don't say there are conflicts to resolve when there are no conflict
-      # files.
-      conflicts.files.each(&:lines)
-      @conflicts_can_be_resolved_in_ui = conflicts.files.length > 0
-    rescue Rugged::OdbError, Gitlab::Conflict::Parser::UnresolvableError, Gitlab::Conflict::FileCollection::ConflictSideMissing
-      @conflicts_can_be_resolved_in_ui = false
-    end
-  end
-
   def has_commits?
     merge_request_diff && commits_count > 0
   end
diff --git a/app/presenters/merge_request_presenter.rb b/app/presenters/merge_request_presenter.rb
index 255f63db5c2..0db9e31031c 100644
--- a/app/presenters/merge_request_presenter.rb
+++ b/app/presenters/merge_request_presenter.rb
@@ -76,7 +76,7 @@ class MergeRequestPresenter < Gitlab::View::Presenter::Delegated
   end
 
   def conflict_resolution_path
-    if conflicts_can_be_resolved_in_ui? && conflicts_can_be_resolved_by?(current_user)
+    if conflicts.can_be_resolved_in_ui? && conflicts.can_be_resolved_by?(current_user)
       conflicts_namespace_project_merge_request_path(project.namespace, project, merge_request)
     end
   end
@@ -141,6 +141,10 @@ class MergeRequestPresenter < Gitlab::View::Presenter::Delegated
 
   private
 
+  def conflicts
+    @conflicts ||= MergeRequests::Conflicts::ListService.new(merge_request)
+  end
+
   def closing_issues
     @closing_issues ||= closes_issues(current_user)
   end
diff --git a/app/services/merge_requests/conflicts/base_service.rb b/app/services/merge_requests/conflicts/base_service.rb
new file mode 100644
index 00000000000..b50875347d9
--- /dev/null
+++ b/app/services/merge_requests/conflicts/base_service.rb
@@ -0,0 +1,11 @@
+module MergeRequests
+  module Conflicts
+    class BaseService
+      attr_reader :merge_request
+
+      def initialize(merge_request)
+        @merge_request = merge_request
+      end
+    end
+  end
+end
diff --git a/app/services/merge_requests/conflicts/list_service.rb b/app/services/merge_requests/conflicts/list_service.rb
new file mode 100644
index 00000000000..9835606812c
--- /dev/null
+++ b/app/services/merge_requests/conflicts/list_service.rb
@@ -0,0 +1,36 @@
+module MergeRequests
+  module Conflicts
+    class ListService < MergeRequests::Conflicts::BaseService
+      delegate :file_for_path, :to_json, to: :conflicts
+
+      def can_be_resolved_by?(user)
+        return false unless merge_request.source_project
+
+        access = ::Gitlab::UserAccess.new(user, project: merge_request.source_project)
+        access.can_push_to_branch?(merge_request.source_branch)
+      end
+
+      def can_be_resolved_in_ui?
+        return @conflicts_can_be_resolved_in_ui if defined?(@conflicts_can_be_resolved_in_ui)
+
+        return @conflicts_can_be_resolved_in_ui = false unless merge_request.cannot_be_merged?
+        return @conflicts_can_be_resolved_in_ui = false unless merge_request.has_complete_diff_refs?
+        return @conflicts_can_be_resolved_in_ui = false if merge_request.branch_missing?
+
+        begin
+          # Try to parse each conflict. If the MR's mergeable status hasn't been
+          # updated, ensure that we don't say there are conflicts to resolve
+          # when there are no conflict files.
+          conflicts.files.each(&:lines)
+          @conflicts_can_be_resolved_in_ui = conflicts.files.length > 0
+        rescue Rugged::OdbError, Gitlab::Conflict::Parser::UnresolvableError, Gitlab::Conflict::FileCollection::ConflictSideMissing
+          @conflicts_can_be_resolved_in_ui = false
+        end
+      end
+
+      def conflicts
+        @conflicts ||= Gitlab::Conflict::FileCollection.read_only(merge_request)
+      end
+    end
+  end
+end
diff --git a/app/services/merge_requests/conflicts/resolve_service.rb b/app/services/merge_requests/conflicts/resolve_service.rb
new file mode 100644
index 00000000000..d74a82effd6
--- /dev/null
+++ b/app/services/merge_requests/conflicts/resolve_service.rb
@@ -0,0 +1,53 @@
+module MergeRequests
+  module Conflicts
+    class ResolveService < MergeRequests::Conflicts::BaseService
+      MissingFiles = Class.new(Gitlab::Conflict::ResolutionError)
+
+      def execute(current_user, params)
+        rugged = merge_request.source_project.repository.rugged
+
+        Gitlab::Conflict::FileCollection.for_resolution(merge_request) do |conflicts_for_resolution|
+          merge_index = conflicts_for_resolution.merge_index
+
+          params[:files].each do |file_params|
+            conflict_file = conflicts_for_resolution.file_for_path(file_params[:old_path], file_params[:new_path])
+
+            write_resolved_file_to_index(merge_index, rugged, conflict_file, file_params)
+          end
+
+          unless merge_index.conflicts.empty?
+            missing_files = merge_index.conflicts.map { |file| file[:ours][:path] }
+
+            raise MissingFiles, "Missing resolutions for the following files: #{missing_files.join(', ')}"
+          end
+
+          commit_params = {
+            message: params[:commit_message] || conflicts_for_resolution.default_commit_message,
+            parents: [conflicts_for_resolution.our_commit, conflicts_for_resolution.their_commit].map(&:oid),
+            tree: merge_index.write_tree(rugged)
+          }
+
+          conflicts_for_resolution.
+            project.
+            repository.
+            resolve_conflicts(current_user, merge_request.source_branch, commit_params)
+        end
+      end
+
+      private
+
+      def write_resolved_file_to_index(merge_index, rugged, file, params)
+        new_file = if params[:sections]
+                     file.resolve_lines(params[:sections]).map(&:text).join("\n")
+                   elsif params[:content]
+                     file.resolve_content(params[:content])
+                   end
+
+        our_path = file.our_path
+
+        merge_index.add(path: our_path, oid: rugged.write(new_file, :blob), mode: file.our_mode)
+        merge_index.conflict_remove(our_path)
+      end
+    end
+  end
+end
diff --git a/app/services/merge_requests/resolve_service.rb b/app/services/merge_requests/resolve_service.rb
deleted file mode 100644
index 82cd89d9a0b..00000000000
--- a/app/services/merge_requests/resolve_service.rb
+++ /dev/null
@@ -1,65 +0,0 @@
-module MergeRequests
-  class ResolveService < MergeRequests::BaseService
-    MissingFiles = Class.new(Gitlab::Conflict::ResolutionError)
-
-    attr_accessor :conflicts, :rugged, :merge_index, :merge_request
-
-    def execute(merge_request)
-      @conflicts = merge_request.conflicts
-      @rugged = project.repository.rugged
-      @merge_index = conflicts.merge_index
-      @merge_request = merge_request
-
-      fetch_their_commit!
-
-      params[:files].each do |file_params|
-        conflict_file = merge_request.conflicts.file_for_path(file_params[:old_path], file_params[:new_path])
-
-        write_resolved_file_to_index(conflict_file, file_params)
-      end
-
-      unless merge_index.conflicts.empty?
-        missing_files = merge_index.conflicts.map { |file| file[:ours][:path] }
-
-        raise MissingFiles, "Missing resolutions for the following files: #{missing_files.join(', ')}"
-      end
-
-      commit_params = {
-        message: params[:commit_message] || conflicts.default_commit_message,
-        parents: [conflicts.our_commit, conflicts.their_commit].map(&:oid),
-        tree: merge_index.write_tree(rugged)
-      }
-
-      project.repository.resolve_conflicts(current_user, merge_request.source_branch, commit_params)
-    end
-
-    def write_resolved_file_to_index(file, params)
-      new_file = if params[:sections]
-                   file.resolve_lines(params[:sections]).map(&:text).join("\n")
-                 elsif params[:content]
-                   file.resolve_content(params[:content])
-                 end
-
-      our_path = file.our_path
-
-      merge_index.add(path: our_path, oid: rugged.write(new_file, :blob), mode: file.our_mode)
-      merge_index.conflict_remove(our_path)
-    end
-
-    # If their commit (in the target project) doesn't exist in the source project, it
-    # can't be a parent for the merge commit we're about to create. If that's the case,
-    # fetch the target branch ref into the source project so the commit exists in both.
-    #
-    def fetch_their_commit!
-      return if rugged.include?(conflicts.their_commit.oid)
-
-      random_string = SecureRandom.hex
-
-      project.repository.fetch_ref(
-        merge_request.target_project.repository.path_to_repo,
-        "refs/heads/#{merge_request.target_branch}",
-        "refs/tmp/#{random_string}/head"
-      )
-    end
-  end
-end