Merge branch 'mirror-default-branch' into 'master'

Show warning when mirror repository default branch could not be
updated because it has diverged from upstream.

Fixes https://gitlab.com/gitlab-org/gitlab-ee/issues/223

See merge request !138

CHANGELOG-EE

 v 8.5.0 (unreleased)
+  - Show warning when mirror repository default branch could not be updated because it has diverged from upstream.
 
 v 8.4.2
   - Elasticsearch indexer performance improvements

app/services/projects/update_mirror_service.rb

@@ -26,6 +26,8 @@ module Projects
     def update_branches
       local_branches = repository.branches.each_with_object({}) { |branch, branches| branches[branch.name] = branch }
 
+      errors = []
+
       repository.upstream_branches.each do |upstream_branch|
         name = upstream_branch.name
 
@@ -34,20 +36,27 @@ module Projects
         if local_branch.nil?
           result = CreateBranchService.new(project, current_user).execute(name, upstream_branch.target)
           if result[:status] == :error
-            raise UpdateError, result[:message]
+            errors << result[:message]
           end
         elsif local_branch.target == upstream_branch.target
           # Already up to date
         elsif repository.diverged_from_upstream?(name)
           # Cannot be updated
+          if name == project.default_branch
+            errors << "The default branch (#{project.default_branch}) has diverged from its upstream counterpart and could not be updated automatically."
+          end
         else
           begin
             repository.ff_merge(current_user, upstream_branch.target, name)
           rescue GitHooksService::PreReceiveError, Repository::CommitError => e
-            raise UpdateError, e.message
+            errors << e.message
           end
         end
       end
+
+      unless errors.empty?
+        raise UpdateError, errors.join("\n\n")
+      end
     end
 
     def update_tags(&block)

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

@@ -20,9 +20,7 @@
         protected
 
     - if @project.mirror_ever_updated_successfully? && @repository.diverged_from_upstream?(branch.name)
-      - tooltip_message = "The branch could not be updated automatically because it has diverged from its upstream counterpart."
-      - tooltip_message << "<br>To discard the local changes and overwrite the branch with the upstream version, delete it here and choose 'Update Now' above." if can?(current_user, :push_code, @project)
-      %span.label.label-danger.has_tooltip{data: { html: "true", title: tooltip_message }}
+      %span.label.label-danger.has_tooltip{data: { html: "true", title: branch_diverged_tooltip_message }}
         = icon('exclamation-triangle')
         diverged from upstream
 

app/views/projects/commits/_mirror_status.html.haml

@@ -8,3 +8,8 @@
       This project is mirrored from #{link_to import_url, import_url}.
 
       = render "shared/mirror_status"
+
+      - if @ref.present? && @project.mirror_ever_updated_successfully? && @repository.diverged_from_upstream?(@ref)
+        %span.has_tooltip{data: { html: "true", title: branch_diverged_tooltip_message }}
+          = icon('exclamation-triangle')
+          This branch has diverged from upstream.