Merge branch 'master' into '18471-restrict-tag-pushes-protected-tags'

# Conflicts:
#   app/assets/javascripts/dispatcher.js
#   app/assets/stylesheets/pages/projects.scss

42 files changed, 736 insertions, 210 deletions

diff --git a/lib/gitlab/bitbucket_import/importer.rb b/lib/gitlab/bitbucket_import/importer.rb
index 44323b47dca..f4efa20374a 100644
--- a/lib/gitlab/bitbucket_import/importer.rb
+++ b/lib/gitlab/bitbucket_import/importer.rb
@@ -130,8 +130,13 @@ module Gitlab
       end
 
       def create_labels
-        LABELS.each do |label|
-          @labels[label[:title]] = project.labels.create!(label)
+        LABELS.each do |label_params|
+          label = ::Labels::CreateService.new(label_params).execute(project: project)
+          if label.valid?
+            @labels[label_params[:title]] = label
+          else
+            raise "Failed to create label \"#{label_params[:title]}\" for project \"#{project.name_with_namespace}\""
+          end
         end
       end
 
diff --git a/lib/gitlab/ci/build/step.rb b/lib/gitlab/ci/build/step.rb
index 1877429ac46..ee034d9cc56 100644
--- a/lib/gitlab/ci/build/step.rb
+++ b/lib/gitlab/ci/build/step.rb
@@ -7,13 +7,12 @@ module Gitlab
         WHEN_ALWAYS = 'always'.freeze
 
         attr_reader :name
-        attr_writer :script
-        attr_accessor :timeout, :when, :allow_failure
+        attr_accessor :script, :timeout, :when, :allow_failure
 
         class << self
           def from_commands(job)
             self.new(:script).tap do |step|
-              step.script = job.commands
+              step.script = job.commands.split("\n")
               step.timeout = job.timeout
               step.when = WHEN_ON_SUCCESS
             end
@@ -36,10 +35,6 @@ module Gitlab
           @name = name
           @allow_failure = false
         end
-
-        def script
-          @script.split("\n")
-        end
       end
     end
   end
diff --git a/lib/gitlab/ci/status/canceled.rb b/lib/gitlab/ci/status/canceled.rb
index dd6d99e9075..97c121ce7b9 100644
--- a/lib/gitlab/ci/status/canceled.rb
+++ b/lib/gitlab/ci/status/canceled.rb
@@ -13,6 +13,10 @@ module Gitlab
         def icon
           'icon_status_canceled'
         end
+
+        def favicon
+          'favicon_status_canceled'
+        end
       end
     end
   end
diff --git a/lib/gitlab/ci/status/core.rb b/lib/gitlab/ci/status/core.rb
index 3dd2b9e01f6..d4fd83b93f8 100644
--- a/lib/gitlab/ci/status/core.rb
+++ b/lib/gitlab/ci/status/core.rb
@@ -18,6 +18,10 @@ module Gitlab
           raise NotImplementedError
         end
 
+        def favicon
+          raise NotImplementedError
+        end
+
         def label
           raise NotImplementedError
         end
diff --git a/lib/gitlab/ci/status/created.rb b/lib/gitlab/ci/status/created.rb
index 6596d7e01ca..0721bf6ec7c 100644
--- a/lib/gitlab/ci/status/created.rb
+++ b/lib/gitlab/ci/status/created.rb
@@ -13,6 +13,10 @@ module Gitlab
         def icon
           'icon_status_created'
         end
+
+        def favicon
+          'favicon_status_created'
+        end
       end
     end
   end
diff --git a/lib/gitlab/ci/status/failed.rb b/lib/gitlab/ci/status/failed.rb
index c5b5e3203ad..cb75e9383a8 100644
--- a/lib/gitlab/ci/status/failed.rb
+++ b/lib/gitlab/ci/status/failed.rb
@@ -13,6 +13,10 @@ module Gitlab
         def icon
           'icon_status_failed'
         end
+
+        def favicon
+          'favicon_status_failed'
+        end
       end
     end
   end
diff --git a/lib/gitlab/ci/status/manual.rb b/lib/gitlab/ci/status/manual.rb
index 5f28521901d..f8f6c2903ba 100644
--- a/lib/gitlab/ci/status/manual.rb
+++ b/lib/gitlab/ci/status/manual.rb
@@ -13,6 +13,10 @@ module Gitlab
         def icon
           'icon_status_manual'
         end
+
+        def favicon
+          'favicon_status_manual'
+        end
       end
     end
   end
diff --git a/lib/gitlab/ci/status/pending.rb b/lib/gitlab/ci/status/pending.rb
index d30f35a59a2..f40cc1314dc 100644
--- a/lib/gitlab/ci/status/pending.rb
+++ b/lib/gitlab/ci/status/pending.rb
@@ -13,6 +13,10 @@ module Gitlab
         def icon
           'icon_status_pending'
         end
+
+        def favicon
+          'favicon_status_pending'
+        end
       end
     end
   end
diff --git a/lib/gitlab/ci/status/running.rb b/lib/gitlab/ci/status/running.rb
index 2aba3c373c7..1237cd47dc8 100644
--- a/lib/gitlab/ci/status/running.rb
+++ b/lib/gitlab/ci/status/running.rb
@@ -13,6 +13,10 @@ module Gitlab
         def icon
           'icon_status_running'
         end
+
+        def favicon
+          'favicon_status_running'
+        end
       end
     end
   end
diff --git a/lib/gitlab/ci/status/skipped.rb b/lib/gitlab/ci/status/skipped.rb
index 16282aefd03..28005d91503 100644
--- a/lib/gitlab/ci/status/skipped.rb
+++ b/lib/gitlab/ci/status/skipped.rb
@@ -13,6 +13,10 @@ module Gitlab
         def icon
           'icon_status_skipped'
         end
+
+        def favicon
+          'favicon_status_skipped'
+        end
       end
     end
   end
diff --git a/lib/gitlab/ci/status/success.rb b/lib/gitlab/ci/status/success.rb
index c09c5f006e3..88f7758a270 100644
--- a/lib/gitlab/ci/status/success.rb
+++ b/lib/gitlab/ci/status/success.rb
@@ -13,6 +13,10 @@ module Gitlab
         def icon
           'icon_status_success'
         end
+
+        def favicon
+          'favicon_status_success'
+        end
       end
     end
   end
diff --git a/lib/gitlab/ee_compat_check.rb b/lib/gitlab/ee_compat_check.rb
index e0fdf3f3d64..496ee0bdcb0 100644
--- a/lib/gitlab/ee_compat_check.rb
+++ b/lib/gitlab/ee_compat_check.rb
@@ -5,35 +5,44 @@ module Gitlab
     CE_REPO = 'https://gitlab.com/gitlab-org/gitlab-ce.git'.freeze
     EE_REPO = 'https://gitlab.com/gitlab-org/gitlab-ee.git'.freeze
     CHECK_DIR = Rails.root.join('ee_compat_check')
-    MAX_FETCH_DEPTH = 500
     IGNORED_FILES_REGEX = /(VERSION|CHANGELOG\.md:\d+)/.freeze
-
-    attr_reader :repo_dir, :patches_dir, :ce_repo, :ce_branch
+    PLEASE_READ_THIS_BANNER = %Q{
+      ============================================================
+      ===================== PLEASE READ THIS =====================
+      ============================================================
+    }.freeze
+    THANKS_FOR_READING_BANNER = %Q{
+      ============================================================
+      ==================== THANKS FOR READING ====================
+      ============================================================\n
+    }.freeze
+
+    attr_reader :ee_repo_dir, :patches_dir, :ce_repo, :ce_branch, :ee_branch_found
+    attr_reader :failed_files
 
     def initialize(branch:, ce_repo: CE_REPO)
-      @repo_dir = CHECK_DIR.join('repo')
+      @ee_repo_dir = CHECK_DIR.join('ee-repo')
       @patches_dir = CHECK_DIR.join('patches')
       @ce_branch = branch
       @ce_repo = ce_repo
     end
 
     def check
-      ensure_ee_repo
       ensure_patches_dir
-
       generate_patch(ce_branch, ce_patch_full_path)
 
-      Dir.chdir(repo_dir) do
-        step("In the #{repo_dir} directory")
+      ensure_ee_repo
+      Dir.chdir(ee_repo_dir) do
+        step("In the #{ee_repo_dir} directory")
 
         status = catch(:halt_check) do
           ce_branch_compat_check!
-          delete_ee_branch_locally!
+          delete_ee_branches_locally!
           ee_branch_presence_check!
           ee_branch_compat_check!
         end
 
-        delete_ee_branch_locally!
+        delete_ee_branches_locally!
 
         if status.nil?
           true
@@ -46,11 +55,13 @@ module Gitlab
     private
 
     def ensure_ee_repo
-      if Dir.exist?(repo_dir)
-        step("#{repo_dir} already exists")
+      if Dir.exist?(ee_repo_dir)
+        step("#{ee_repo_dir} already exists")
       else
-        cmd = %W[git clone --branch master --single-branch --depth 200 #{EE_REPO} #{repo_dir}]
-        step("Cloning #{EE_REPO} into #{repo_dir}", cmd)
+        step(
+          "Cloning #{EE_REPO} into #{ee_repo_dir}",
+          %W[git clone --branch master --single-branch --depth=200 #{EE_REPO} #{ee_repo_dir}]
+        )
       end
     end
 
@@ -61,23 +72,18 @@ module Gitlab
     def generate_patch(branch, patch_path)
       FileUtils.rm(patch_path, force: true)
 
-      depth = 0
-      loop do
-        depth += 50
-        cmd = %W[git fetch --depth #{depth} origin --prune +refs/heads/master:refs/remotes/origin/master]
-        Gitlab::Popen.popen(cmd)
-        _, status = Gitlab::Popen.popen(%w[git merge-base FETCH_HEAD HEAD])
+      find_merge_base_with_master(branch: branch)
 
-        raise "#{branch} is too far behind master, please rebase it!" if depth >= MAX_FETCH_DEPTH
-        break if status.zero?
-      end
+      step(
+        "Generating the patch against origin/master in #{patch_path}",
+        %w[git format-patch origin/master --stdout]
+      ) do |output, status|
+        throw(:halt_check, :ko) unless status.zero?
 
-      step("Generating the patch against master in #{patch_path}")
-      output, status = Gitlab::Popen.popen(%w[git format-patch FETCH_HEAD --stdout])
-      throw(:halt_check, :ko) unless status.zero?
+        File.write(patch_path, output)
 
-      File.write(patch_path, output)
-      throw(:halt_check, :ko) unless File.exist?(patch_path)
+        throw(:halt_check, :ko) unless File.exist?(patch_path)
+      end
     end
 
     def ce_branch_compat_check!
@@ -88,9 +94,17 @@ module Gitlab
     end
 
     def ee_branch_presence_check!
-      status = step("Fetching origin/#{ee_branch}", %W[git fetch origin #{ee_branch}])
+      _, status = step("Fetching origin/#{ee_branch_prefix}", %W[git fetch origin #{ee_branch_prefix}])
 
-      unless status.zero?
+      if status.zero?
+        @ee_branch_found = ee_branch_prefix
+      else
+        _, status = step("Fetching origin/#{ee_branch_suffix}", %W[git fetch origin #{ee_branch_suffix}])
+      end
+
+      if status.zero?
+        @ee_branch_found = ee_branch_suffix
+      else
         puts
         puts ce_branch_doesnt_apply_cleanly_and_no_ee_branch_msg
 
@@ -99,9 +113,9 @@ module Gitlab
     end
 
     def ee_branch_compat_check!
-      step("Checking out origin/#{ee_branch}", %W[git checkout -b #{ee_branch} FETCH_HEAD])
+      step("Checking out origin/#{ee_branch_found}", %W[git checkout -b #{ee_branch_found} FETCH_HEAD])
 
-      generate_patch(ee_branch, ee_patch_full_path)
+      generate_patch(ee_branch_found, ee_patch_full_path)
 
       unless check_patch(ee_patch_full_path).zero?
         puts
@@ -111,41 +125,77 @@ module Gitlab
       end
 
       puts
-      puts applies_cleanly_msg(ee_branch)
+      puts applies_cleanly_msg(ee_branch_found)
     end
 
     def check_patch(patch_path)
       step("Checking out master", %w[git checkout master])
-      step("Reseting to latest master", %w[git reset --hard origin/master])
-
-      step("Checking if #{patch_path} applies cleanly to EE/master")
-      output, status = Gitlab::Popen.popen(%W[git apply --check --3way #{patch_path}])
-
-      unless status.zero?
-        failed_files = output.lines.reduce([]) do |memo, line|
-          if line.start_with?('error: patch failed:')
-            file = line.sub(/\Aerror: patch failed: /, '')
-            memo << file unless file =~ IGNORED_FILES_REGEX
+      step("Resetting to latest master", %w[git reset --hard origin/master])
+      step(
+        "Checking if #{patch_path} applies cleanly to EE/master",
+        %W[git apply --check --3way #{patch_path}]
+      ) do |output, status|
+        unless status.zero?
+          @failed_files = output.lines.reduce([]) do |memo, line|
+            if line.start_with?('error: patch failed:')
+              file = line.sub(/\Aerror: patch failed: /, '')
+              memo << file unless file =~ IGNORED_FILES_REGEX
+            end
+            memo
           end
-          memo
+
+          status = 0 if failed_files.empty?
         end
 
-        if failed_files.empty?
-          status = 0
-        else
-          puts "\nConflicting files:"
-          failed_files.each do |file|
-            puts "  - #{file}"
-          end
+        status
+      end
+    end
+
+    def delete_ee_branches_locally!
+      command(%w[git checkout master])
+      command(%W[git branch --delete --force #{ee_branch_prefix}])
+      command(%W[git branch --delete --force #{ee_branch_suffix}])
+    end
+
+    def merge_base_found?
+      step(
+        "Finding merge base with master",
+        %w[git merge-base origin/master HEAD]
+      ) do |output, status|
+        if status.zero?
+          puts "Merge base was found: #{output}"
+          true
         end
       end
+    end
+
+    def find_merge_base_with_master(branch:)
+      return if merge_base_found?
+
+      # Start with (Math.exp(3).to_i = 20) until (Math.exp(6).to_i = 403)
+      # In total we go (20 + 54 + 148 + 403 = 625) commits deeper
+      depth = 20
+      success =
+        (3..6).any? do |factor|
+          depth += Math.exp(factor).to_i
+          # Repository is initially cloned with a depth of 20 so we need to fetch
+          # deeper in the case the branch has more than 20 commits on top of master
+          fetch(branch: branch, depth: depth)
+          fetch(branch: 'master', depth: depth)
+
+          merge_base_found?
+        end
 
-      status
+      raise "\n#{branch} is too far behind master, please rebase it!\n" unless success
     end
 
-    def delete_ee_branch_locally!
-      command(%w[git checkout master])
-      step("Deleting the local #{ee_branch} branch", %W[git branch -D #{ee_branch}])
+    def fetch(branch:, depth:)
+      step(
+        "Fetching deeper...",
+        %W[git fetch --depth=#{depth} --prune origin +refs/heads/#{branch}:refs/remotes/origin/#{branch}]
+      ) do |output, status|
+        raise "Fetch failed: #{output}" unless status.zero?
+      end
     end
 
     def ce_patch_name
@@ -156,12 +206,16 @@ module Gitlab
       @ce_patch_full_path ||= patches_dir.join(ce_patch_name)
     end
 
-    def ee_branch
-      @ee_branch ||= "#{ce_branch}-ee"
+    def ee_branch_suffix
+      @ee_branch_suffix ||= "#{ce_branch}-ee"
+    end
+
+    def ee_branch_prefix
+      @ee_branch_prefix ||= "ee-#{ce_branch}"
     end
 
     def ee_patch_name
-      @ee_patch_name ||= patch_name_from_branch(ee_branch)
+      @ee_patch_name ||= patch_name_from_branch(ee_branch_found)
     end
 
     def ee_patch_full_path
@@ -178,98 +232,125 @@ module Gitlab
       if cmd
         start = Time.now
         puts "\n$ #{cmd.join(' ')}"
-        status = command(cmd)
-        puts "\nFinished in #{Time.now - start} seconds"
-        status
+
+        output, status = command(cmd)
+        puts "\n==> Finished in #{Time.now - start} seconds"
+
+        if block_given?
+          yield(output, status)
+        else
+          [output, status]
+        end
       end
     end
 
     def command(cmd)
-      output, status = Gitlab::Popen.popen(cmd)
-      puts output
-
-      status
+      Gitlab::Popen.popen(cmd)
     end
 
     def applies_cleanly_msg(branch)
-      <<-MSG.strip_heredoc
-        =================================================================
+      %Q{
+        #{PLEASE_READ_THIS_BANNER}
         🎉 Congratulations!! 🎉
 
-        The #{branch} branch applies cleanly to EE/master!
+        The `#{branch}` branch applies cleanly to EE/master!
 
-        Much ❤️!!
-        =================================================================\n
-      MSG
+        Much ❤️! For more information, see
+        https://docs.gitlab.com/ce/development/limit_ee_conflicts.html#check-the-rake-ee_compat_check-in-your-merge-requests
+        #{THANKS_FOR_READING_BANNER}
+      }
     end
 
     def ce_branch_doesnt_apply_cleanly_and_no_ee_branch_msg
-      <<-MSG.strip_heredoc
-        =================================================================
+      %Q{
+        #{PLEASE_READ_THIS_BANNER}
         💥 Oh no! 💥
 
-        The #{ce_branch} branch does not apply cleanly to the current
-        EE/master, and no #{ee_branch} branch was found in the EE repository.
+        The `#{ce_branch}` branch does not apply cleanly to the current
+        EE/master, and no `#{ee_branch_prefix}` or `#{ee_branch_suffix}` branch
+        was found in the EE repository.
 
-        Please create a #{ee_branch} branch that includes changes from
-        #{ce_branch} but also specific changes than can be applied cleanly
-        to EE/master.
+        #{conflicting_files_msg}
+
+        We advise you to create a `#{ee_branch_prefix}` or `#{ee_branch_suffix}`
+        branch that includes changes from `#{ce_branch}` but also specific changes
+        than can be applied cleanly to EE/master. In some cases, the conflicts
+        are trivial and you can ignore the warning from this job. As always,
+        use your best judgment!
 
         There are different ways to create such branch:
 
-        1. Create a new branch based on the CE branch and rebase it on top of EE/master
+        1. Create a new branch from master and cherry-pick your CE commits
 
           # In the EE repo
-          $ git fetch #{ce_repo} #{ce_branch}
-          $ git checkout -b #{ee_branch} FETCH_HEAD
-
-          # You can squash the #{ce_branch} commits into a single "Port of #{ce_branch} to EE" commit
-          # before rebasing to limit the conflicts-resolving steps during the rebase
           $ git fetch origin
-          $ git rebase origin/master
+          $ git checkout -b #{ee_branch_prefix} origin/master
+          $ git fetch #{ce_repo} #{ce_branch}
+          $ git cherry-pick SHA # Repeat for all the commits you want to pick
 
-          At this point you will likely have conflicts.
-          Solve them, and continue/finish the rebase.
+          You can squash the `#{ce_branch}` commits into a single "Port of #{ce_branch} to EE" commit.
 
-          You can squash the #{ce_branch} commits into a single "Port of #{ce_branch} to EE".
+        2. Apply your branch's patch to EE
 
-        2. Create a new branch from master and cherry-pick your CE commits
+          # In the CE repo
+          $ git fetch origin master
+          $ git format-patch origin/master --stdout > #{ce_branch}.patch
 
           # In the EE repo
-          $ git fetch origin
-          $ git checkout -b #{ee_branch} origin/master
-          $ git fetch #{ce_repo} #{ce_branch}
-          $ git cherry-pick SHA # Repeat for all the commits you want to pick
+          $ git fetch origin master
+          $ git checkout -b #{ee_branch_prefix} origin/master
+          $ git apply --3way path/to/#{ce_branch}.patch
+
+          At this point you might have conflicts such as:
 
-          You can squash the #{ce_branch} commits into a single "Port of #{ce_branch} to EE" commit.
+            error: patch failed: lib/gitlab/ee_compat_check.rb:5
+            Falling back to three-way merge...
+            Applied patch to 'lib/gitlab/ee_compat_check.rb' with conflicts.
+            U lib/gitlab/ee_compat_check.rb
 
-        Don't forget to push your branch to #{EE_REPO}:
+          Resolve them, stage the changes and commit them.
+
+        ⚠️ Don't forget to push your branch to gitlab-ee:
 
           # In the EE repo
-          $ git push origin #{ee_branch}
+          $ git push origin #{ee_branch_prefix}
+
+        ⚠️ Also, don't forget to create a new merge request on gitlab-ce and
+        cross-link it with the CE merge request.
 
-        You can then retry this failed build, and hopefully it should pass.
+        Once this is done, you can retry this failed build, and it should pass.
 
-        Stay 💪 !
-        =================================================================\n
-      MSG
+        Stay 💪 ! For more information, see
+        https://docs.gitlab.com/ce/development/limit_ee_conflicts.html#check-the-rake-ee_compat_check-in-your-merge-requests
+        #{THANKS_FOR_READING_BANNER}
+      }
     end
 
     def ee_branch_doesnt_apply_cleanly_msg
-      <<-MSG.strip_heredoc
-        =================================================================
+      %Q{
+        #{PLEASE_READ_THIS_BANNER}
         💥 Oh no! 💥
 
-        The #{ce_branch} does not apply cleanly to the current
-        EE/master, and even though a #{ee_branch} branch exists in the EE
-        repository, it does not apply cleanly either to EE/master!
+        The `#{ce_branch}` does not apply cleanly to the current EE/master, and
+        even though a `#{ee_branch_found}` branch
+        exists in the EE repository, it does not apply cleanly either to
+        EE/master!
+
+        #{conflicting_files_msg}
 
-        Please update the #{ee_branch}, push it again to #{EE_REPO}, and
+        Please update the `#{ee_branch_found}`, push it again to gitlab-ee, and
         retry this build.
 
-        Stay 💪 !
-        =================================================================\n
-      MSG
+        Stay 💪 ! For more information, see
+        https://docs.gitlab.com/ce/development/limit_ee_conflicts.html#check-the-rake-ee_compat_check-in-your-merge-requests
+        #{THANKS_FOR_READING_BANNER}
+      }
+    end
+
+    def conflicting_files_msg
+      failed_files.reduce("The conflicts detected were as follows:\n") do |memo, file|
+        memo << "\n        - #{file}"
+      end
     end
   end
 end
diff --git a/lib/gitlab/etag_caching/middleware.rb b/lib/gitlab/etag_caching/middleware.rb
index ffbc6e17dc5..cd4e318033d 100644
--- a/lib/gitlab/etag_caching/middleware.rb
+++ b/lib/gitlab/etag_caching/middleware.rb
@@ -1,9 +1,10 @@
 module Gitlab
   module EtagCaching
     class Middleware
-      RESERVED_WORDS = ProjectPathValidator::RESERVED.map { |word| "/#{word}/" }.join('|')
+      RESERVED_WORDS = NamespaceValidator::WILDCARD_ROUTES.map { |word| "/#{word}/" }.join('|')
       ROUTE_REGEXP = Regexp.union(
-        %r(^(?!.*(#{RESERVED_WORDS})).*/noteable/issue/\d+/notes\z)
+        %r(^(?!.*(#{RESERVED_WORDS})).*/noteable/issue/\d+/notes\z),
+        %r(^(?!.*(#{RESERVED_WORDS})).*/issues/\d+/rendered_title\z)
       )
 
       def initialize(app)
@@ -18,8 +19,7 @@ module Gitlab
         if_none_match = env['HTTP_IF_NONE_MATCH']
 
         if if_none_match == etag
-          Gitlab::Metrics.add_event(:etag_caching_cache_hit)
-          [304, { 'ETag' => etag }, ['']]
+          handle_cache_hit(etag)
         else
           track_cache_miss(if_none_match, cached_value_present)
 
@@ -52,6 +52,14 @@ module Gitlab
         %Q{W/"#{value}"}
       end
 
+      def handle_cache_hit(etag)
+        Gitlab::Metrics.add_event(:etag_caching_cache_hit)
+
+        status_code = Gitlab::PollingInterval.polling_enabled? ? 304 : 429
+
+        [status_code, { 'ETag' => etag }, ['']]
+      end
+
       def track_cache_miss(if_none_match, cached_value_present)
         if if_none_match.blank?
           Gitlab::Metrics.add_event(:etag_caching_header_missing)
diff --git a/lib/gitlab/etag_caching/store.rb b/lib/gitlab/etag_caching/store.rb
index 9532e432f78..0039fc01c8f 100644
--- a/lib/gitlab/etag_caching/store.rb
+++ b/lib/gitlab/etag_caching/store.rb
@@ -1,7 +1,7 @@
 module Gitlab
   module EtagCaching
     class Store
-      EXPIRY_TIME = 10.minutes
+      EXPIRY_TIME = 20.minutes
       REDIS_NAMESPACE = 'etag:'.freeze
 
       def get(key)
diff --git a/lib/gitlab/git.rb b/lib/gitlab/git.rb
index d3df3f1bca1..936606152e9 100644
--- a/lib/gitlab/git.rb
+++ b/lib/gitlab/git.rb
@@ -4,6 +4,8 @@ module Gitlab
     TAG_REF_PREFIX = "refs/tags/".freeze
     BRANCH_REF_PREFIX = "refs/heads/".freeze
 
+    CommandError = Class.new(StandardError)
+
     class << self
       def ref_name(ref)
         ref.sub(/\Arefs\/(tags|heads)\//, '')
diff --git a/lib/gitlab/git/repository.rb b/lib/gitlab/git/repository.rb
index 2187dd70ff4..2e4314932c8 100644
--- a/lib/gitlab/git/repository.rb
+++ b/lib/gitlab/git/repository.rb
@@ -25,9 +25,13 @@ module Gitlab
 
       # 'path' must be the path to a _bare_ git repository, e.g.
       # /path/to/my-repo.git
-      def initialize(path)
-        @path = path
-        @name = path.split("/").last
+      def initialize(repository_storage, relative_path)
+        @repository_storage = repository_storage
+        @relative_path = relative_path
+
+        storage_path = Gitlab.config.repositories.storages[@repository_storage]['path']
+        @path = File.join(storage_path, @relative_path)
+        @name = @relative_path.split("/").last
         @attributes = Gitlab::Git::Attributes.new(path)
       end
 
@@ -37,7 +41,15 @@ module Gitlab
 
       # Default branch in the repository
       def root_ref
-        @root_ref ||= discover_default_branch
+        @root_ref ||= Gitlab::GitalyClient.migrate(:root_ref) do |is_enabled|
+          if is_enabled
+            gitaly_ref_client.default_branch_name
+          else
+            discover_default_branch
+          end
+        end
+      rescue GRPC::BadStatus => e
+        raise CommandError.new(e)
       end
 
       # Alias to old method for compatibility
@@ -54,7 +66,15 @@ module Gitlab
       # Returns an Array of branch names
       # sorted by name ASC
       def branch_names
-        branches.map(&:name)
+        Gitlab::GitalyClient.migrate(:branch_names) do |is_enabled|
+          if is_enabled
+            gitaly_ref_client.branch_names
+          else
+            branches.map(&:name)
+          end
+        end
+      rescue GRPC::BadStatus => e
+        raise CommandError.new(e)
       end
 
       # Returns an Array of Branches
@@ -107,7 +127,15 @@ module Gitlab
 
       # Returns an Array of tag names
       def tag_names
-        rugged.tags.map { |t| t.name }
+        Gitlab::GitalyClient.migrate(:tag_names) do |is_enabled|
+          if is_enabled
+            gitaly_ref_client.tag_names
+          else
+            rugged.tags.map { |t| t.name }
+          end
+        end
+      rescue GRPC::BadStatus => e
+        raise CommandError.new(e)
       end
 
       # Returns an Array of Tags
@@ -320,7 +348,7 @@ module Gitlab
       def log_by_walk(sha, options)
         walk_options = {
           show: sha,
-          sort: Rugged::SORT_DATE,
+          sort: Rugged::SORT_NONE,
           limit: options[:limit],
           offset: options[:offset]
         }
@@ -346,7 +374,12 @@ module Gitlab
         cmd << "--after=#{options[:after].iso8601}" if options[:after]
         cmd << "--before=#{options[:before].iso8601}" if options[:before]
         cmd << sha
-        cmd += %W[-- #{options[:path]}] if options[:path].present?
+
+        # :path can be a string or an array of strings
+        if options[:path].present?
+          cmd << '--'
+          cmd += Array(options[:path])
+        end
 
         raw_output = IO.popen(cmd) { |io| io.read }
         lines = offset_in_ruby ? raw_output.lines.drop(offset) : raw_output.lines
@@ -382,7 +415,7 @@ module Gitlab
       # a detailed list of valid arguments.
       def commits_between(from, to)
         walker = Rugged::Walker.new(rugged)
-        walker.sorting(Rugged::SORT_DATE | Rugged::SORT_REVERSE)
+        walker.sorting(Rugged::SORT_NONE | Rugged::SORT_REVERSE)
 
         sha_from = sha_from_ref(from)
         sha_to = sha_from_ref(to)
@@ -406,6 +439,11 @@ module Gitlab
         rugged.merge_base(from, to)
       end
 
+      # Returns true is +from+ is direct ancestor to +to+, otherwise false
+      def is_ancestor?(from, to)
+        Gitlab::GitalyClient::Commit.is_ancestor(self, from, to)
+      end
+
       # Return an array of Diff objects that represent the diff
       # between +from+ and +to+.  See Diff::filter_diff_options for the allowed
       # diff options.  The +options+ hash can also include :break_rewrites to
@@ -460,7 +498,7 @@ module Gitlab
         if actual_options[:order] == :topo
           walker.sorting(Rugged::SORT_TOPO)
         else
-          walker.sorting(Rugged::SORT_DATE)
+          walker.sorting(Rugged::SORT_NONE)
         end
 
         commits = []
@@ -828,23 +866,6 @@ module Gitlab
         Rugged::Commit.create(rugged, actual_options)
       end
 
-      def commits_since(from_date)
-        walker = Rugged::Walker.new(rugged)
-        walker.sorting(Rugged::SORT_DATE | Rugged::SORT_REVERSE)
-
-        rugged.references.each("refs/heads/*") do |ref|
-          walker.push(ref.target_id)
-        end
-
-        commits = []
-        walker.each do |commit|
-          break if commit.author[:time].to_date < from_date
-          commits.push(commit)
-        end
-
-        commits
-      end
-
       AUTOCRLF_VALUES = {
         "true" => true,
         "false" => false,
@@ -1209,6 +1230,10 @@ module Gitlab
         diff.find_similar!(break_rewrites: break_rewrites)
         diff.each_patch
       end
+
+      def gitaly_ref_client
+        @gitaly_ref_client ||= Gitlab::GitalyClient::Ref.new(@repository_storage, @relative_path)
+      end
     end
   end
 end
diff --git a/lib/gitlab/git/tree.rb b/lib/gitlab/git/tree.rb
index f7450e8b58f..b722d8a9f56 100644
--- a/lib/gitlab/git/tree.rb
+++ b/lib/gitlab/git/tree.rb
@@ -33,7 +33,7 @@ module Gitlab
               root_id: root_tree.oid,
               name: entry[:name],
               type: entry[:type],
-              mode: entry[:filemode],
+              mode: entry[:filemode].to_s(8),
               path: path ? File.join(path, entry[:name]) : entry[:name],
               commit_id: sha,
             )
diff --git a/lib/gitlab/gitaly_client.rb b/lib/gitlab/gitaly_client.rb
index 5534d4af439..bcdf1b1faa8 100644
--- a/lib/gitlab/gitaly_client.rb
+++ b/lib/gitlab/gitaly_client.rb
@@ -2,28 +2,62 @@ require 'gitaly'
 
 module Gitlab
   module GitalyClient
-    def self.gitaly_address
-      if Gitlab.config.gitaly.socket_path
-        "unix://#{Gitlab.config.gitaly.socket_path}"
+    SERVER_VERSION_FILE = 'GITALY_SERVER_VERSION'.freeze
+
+    # This function is not thread-safe because it updates Hashes in instance variables.
+    def self.configure_channels
+      @addresses = {}
+      @channels = {}
+      Gitlab.config.repositories.storages.each do |name, params|
+        address = params['gitaly_address']
+        unless address.present?
+          raise "storage #{name.inspect} is missing a gitaly_address"
+        end
+
+        unless URI(address).scheme.in?(%w(tcp unix))
+          raise "Unsupported Gitaly address: #{address.inspect}"
+        end
+
+        @addresses[name] = address
+        @channels[name] = new_channel(address)
       end
     end
 
-    def self.channel
-      return @channel if defined?(@channel)
+    def self.new_channel(address)
+      address = address.sub(%r{^tcp://}, '') if URI(address).scheme == 'tcp'
+      # NOTE: When Gitaly runs on a Unix socket, permissions are
+      # handled using the file system and no additional authentication is
+      # required (therefore the :this_channel_is_insecure flag)
+      # TODO: Add authentication support when Gitaly is running on a TCP socket.
+      GRPC::Core::Channel.new(address, {}, :this_channel_is_insecure)
+    end
 
-      @channel =
-        if enabled?
-          # NOTE: Gitaly currently runs on a Unix socket, so permissions are
-          # handled using the file system and no additional authentication is
-          # required (therefore the :this_channel_is_insecure flag)
-          GRPC::Core::Channel.new(gitaly_address, {}, :this_channel_is_insecure)
-        else
-          nil
-        end
+    def self.get_channel(storage)
+      if !Rails.env.production? && @channels.nil?
+        # In development mode the Rails auto-loader may reset the instance
+        # variables of this class. What we do here is not thread-safe. In normal
+        # circumstances (including production) these instance variables have
+        # been initialized from config/initializers.
+        configure_channels
+      end
+
+      @channels[storage]
+    end
+
+    def self.get_address(storage)
+      if !Rails.env.production? && @addresses.nil?
+        # In development mode the Rails auto-loader may reset the instance
+        # variables of this class. What we do here is not thread-safe. In normal
+        # circumstances (including development) these instance variables have
+        # been initialized from config/initializers.
+        configure_channels
+      end
+
+      @addresses[storage]
     end
 
     def self.enabled?
-      gitaly_address.present?
+      Gitlab.config.gitaly.enabled
     end
 
     def self.feature_enabled?(feature)
@@ -39,5 +73,10 @@ module Gitlab
         yield is_enabled
       end
     end
+
+    def self.expected_server_version
+      path = Rails.root.join(SERVER_VERSION_FILE)
+      path.read.chomp
+    end
   end
 end
diff --git a/lib/gitlab/gitaly_client/commit.rb b/lib/gitlab/gitaly_client/commit.rb
index 525b8d680e9..f15faebe27e 100644
--- a/lib/gitlab/gitaly_client/commit.rb
+++ b/lib/gitlab/gitaly_client/commit.rb
@@ -7,8 +7,10 @@ module Gitlab
 
       class << self
         def diff_from_parent(commit, options = {})
-          stub      = Gitaly::Diff::Stub.new(nil, nil, channel_override: GitalyClient.channel)
-          repo      = Gitaly::Repository.new(path: commit.project.repository.path_to_repo)
+          project   = commit.project
+          channel   = GitalyClient.get_channel(project.repository_storage)
+          stub      = Gitaly::Diff::Stub.new(nil, nil, channel_override: channel)
+          repo      = Gitaly::Repository.new(path: project.repository.path_to_repo)
           parent    = commit.parents[0]
           parent_id = parent ? parent.id : EMPTY_TREE_ID
           request   = Gitaly::CommitDiffRequest.new(
@@ -19,6 +21,20 @@ module Gitlab
 
           Gitlab::Git::DiffCollection.new(stub.commit_diff(request), options)
         end
+
+        def is_ancestor(repository, ancestor_id, child_id)
+          project = Project.find_by_path(repository.path)
+          channel = GitalyClient.get_channel(project.repository_storage)
+          stub = Gitaly::Commit::Stub.new(nil, nil, channel_override: channel)
+          repo = Gitaly::Repository.new(path: repository.path_to_repo)
+          request = Gitaly::CommitIsAncestorRequest.new(
+            repository: repo,
+            ancestor_id: ancestor_id,
+            child_id: child_id
+          )
+
+          stub.commit_is_ancestor(request).value
+        end
       end
     end
   end
diff --git a/lib/gitlab/gitaly_client/notifications.rb b/lib/gitlab/gitaly_client/notifications.rb
index b827a56207f..f0d93ded91b 100644
--- a/lib/gitlab/gitaly_client/notifications.rb
+++ b/lib/gitlab/gitaly_client/notifications.rb
@@ -3,14 +3,14 @@ module Gitlab
     class Notifications
       attr_accessor :stub
 
-      def initialize
-        @stub = Gitaly::Notifications::Stub.new(nil, nil, channel_override: GitalyClient.channel)
+      def initialize(repository_storage, relative_path)
+        @channel, @repository = Util.process_path(repository_storage, relative_path)
+        @stub = Gitaly::Notifications::Stub.new(nil, nil, channel_override: @channel)
       end
 
-      def post_receive(repo_path)
-        repository = Gitaly::Repository.new(path: repo_path)
-        request = Gitaly::PostReceiveRequest.new(repository: repository)
-        stub.post_receive(request)
+      def post_receive
+        request = Gitaly::PostReceiveRequest.new(repository: @repository)
+        @stub.post_receive(request)
       end
     end
   end
diff --git a/lib/gitlab/gitaly_client/ref.rb b/lib/gitlab/gitaly_client/ref.rb
new file mode 100644
index 00000000000..bfc5fa573c7
--- /dev/null
+++ b/lib/gitlab/gitaly_client/ref.rb
@@ -0,0 +1,35 @@
+module Gitlab
+  module GitalyClient
+    class Ref
+      attr_accessor :stub
+
+      def initialize(repository_storage, relative_path)
+        @channel, @repository = Util.process_path(repository_storage, relative_path)
+        @stub = Gitaly::Ref::Stub.new(nil, nil, channel_override: @channel)
+      end
+
+      def default_branch_name
+        request = Gitaly::FindDefaultBranchNameRequest.new(repository: @repository)
+        stub.find_default_branch_name(request).name.gsub(/^refs\/heads\//, '')
+      end
+
+      def branch_names
+        request = Gitaly::FindAllBranchNamesRequest.new(repository: @repository)
+        consume_refs_response(stub.find_all_branch_names(request), prefix: 'refs/heads/')
+      end
+
+      def tag_names
+        request = Gitaly::FindAllTagNamesRequest.new(repository: @repository)
+        consume_refs_response(stub.find_all_tag_names(request), prefix: 'refs/tags/')
+      end
+
+      private
+
+      def consume_refs_response(response, prefix:)
+        response.flat_map do |r|
+          r.names.map { |name| name.sub(/\A#{Regexp.escape(prefix)}/, '') }
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/gitaly_client/util.rb b/lib/gitlab/gitaly_client/util.rb
new file mode 100644
index 00000000000..d272c25d1f9
--- /dev/null
+++ b/lib/gitlab/gitaly_client/util.rb
@@ -0,0 +1,13 @@
+module Gitlab
+  module GitalyClient
+    module Util
+      def self.process_path(repository_storage, relative_path)
+        channel = GitalyClient.get_channel(repository_storage)
+        storage_path = Gitlab.config.repositories.storages[repository_storage]['path']
+        repository = Gitaly::Repository.new(path: File.join(storage_path, relative_path))
+
+        [channel, repository]
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/github_import/branch_formatter.rb b/lib/gitlab/github_import/branch_formatter.rb
index 5d29e698b27..8aa885fb811 100644
--- a/lib/gitlab/github_import/branch_formatter.rb
+++ b/lib/gitlab/github_import/branch_formatter.rb
@@ -11,6 +11,14 @@ module Gitlab
         sha.present? && ref.present?
       end
 
+      def user
+        raw_data.user&.login || 'unknown'
+      end
+
+      def short_sha
+        Commit.truncate_sha(sha)
+      end
+
       private
 
       def branch_exists?
diff --git a/lib/gitlab/github_import/importer.rb b/lib/gitlab/github_import/importer.rb
index eea4a91f17d..a8c0b47e786 100644
--- a/lib/gitlab/github_import/importer.rb
+++ b/lib/gitlab/github_import/importer.rb
@@ -157,7 +157,7 @@ module Gitlab
       end
 
       def restore_source_branch(pull_request)
-        project.repository.fetch_ref(repo_url, "pull/#{pull_request.number}/head", pull_request.source_branch_name)
+        project.repository.create_branch(pull_request.source_branch_name, pull_request.source_branch_sha)
       end
 
       def restore_target_branch(pull_request)
diff --git a/lib/gitlab/github_import/pull_request_formatter.rb b/lib/gitlab/github_import/pull_request_formatter.rb
index add7236e339..150afa31432 100644
--- a/lib/gitlab/github_import/pull_request_formatter.rb
+++ b/lib/gitlab/github_import/pull_request_formatter.rb
@@ -1,8 +1,8 @@
 module Gitlab
   module GithubImport
     class PullRequestFormatter < IssuableFormatter
-      delegate :exists?, :project, :ref, :repo, :sha, to: :source_branch, prefix: true
-      delegate :exists?, :project, :ref, :repo, :sha, to: :target_branch, prefix: true
+      delegate :user, :project, :ref, :repo, :sha, to: :source_branch, prefix: true
+      delegate :user, :exists?, :project, :ref, :repo, :sha, :short_sha, to: :target_branch, prefix: true
 
       def attributes
         {
@@ -20,7 +20,8 @@ module Gitlab
           author_id: author_id,
           assignee_id: assignee_id,
           created_at: raw_data.created_at,
-          updated_at: raw_data.updated_at
+          updated_at: raw_data.updated_at,
+          imported: true
         }
       end
 
@@ -37,13 +38,20 @@ module Gitlab
       end
 
       def source_branch_name
-        @source_branch_name ||= begin
-          if cross_project?
-            "pull/#{number}/#{source_branch_repo.full_name}/#{source_branch_ref}"
+        @source_branch_name ||=
+          if cross_project? || !source_branch_exists?
+            source_branch_name_prefixed
           else
-            source_branch_exists? ? source_branch_ref : "pull/#{number}/#{source_branch_ref}"
+            source_branch_ref
           end
-        end
+      end
+
+      def source_branch_name_prefixed
+        "gh-#{target_branch_short_sha}/#{number}/#{source_branch_user}/#{source_branch_ref}"
+      end
+
+      def source_branch_exists?
+        !cross_project? && source_branch.exists?
       end
 
       def target_branch
@@ -51,13 +59,17 @@ module Gitlab
       end
 
       def target_branch_name
-        @target_branch_name ||= begin
-          target_branch_exists? ? target_branch_ref : "pull/#{number}/#{target_branch_ref}"
-        end
+        @target_branch_name ||= target_branch_exists? ? target_branch_ref : target_branch_name_prefixed
+      end
+
+      def target_branch_name_prefixed
+        "gl-#{target_branch_short_sha}/#{number}/#{target_branch_user}/#{target_branch_ref}"
       end
 
       def cross_project?
-        source_branch.repo.id != target_branch.repo.id
+        return true if source_branch_repo.nil?
+
+        source_branch_repo.id != target_branch_repo.id
       end
 
       def opened?
diff --git a/lib/gitlab/import_export/hash_util.rb b/lib/gitlab/import_export/hash_util.rb
new file mode 100644
index 00000000000..d4adeeb3797
--- /dev/null
+++ b/lib/gitlab/import_export/hash_util.rb
@@ -0,0 +1,25 @@
+module Gitlab
+  module ImportExport
+    class HashUtil
+      def self.deep_symbolize_array!(array)
+        return if array.blank?
+
+        array.map! do |hash|
+          hash.deep_symbolize_keys!
+
+          yield(hash) if block_given?
+
+          hash
+        end
+      end
+
+      def self.deep_symbolize_array_with_date!(array)
+        self.deep_symbolize_array!(array) do |hash|
+          hash.select { |k, _v| k.to_s.end_with?('_date') }.each do |key, value|
+            hash[key] = Time.zone.parse(value)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/import_export/import_export.yml b/lib/gitlab/import_export/import_export.yml
index 25e03ec64d3..745f9a1cfbd 100644
--- a/lib/gitlab/import_export/import_export.yml
+++ b/lib/gitlab/import_export/import_export.yml
@@ -91,3 +91,5 @@ methods:
     - :type
   merge_request_diff:
     - :utf8_st_diffs
+  merge_requests:
+    - :diff_head_sha
diff --git a/lib/gitlab/import_export/importer.rb b/lib/gitlab/import_export/importer.rb
index 063ce74ecad..fbdd74788bc 100644
--- a/lib/gitlab/import_export/importer.rb
+++ b/lib/gitlab/import_export/importer.rb
@@ -9,7 +9,7 @@ module Gitlab
       end
 
       def execute
-        if import_file && check_version! && [project_tree, avatar_restorer, repo_restorer, wiki_restorer, uploads_restorer].all?(&:restore)
+        if import_file && check_version! && [repo_restorer, wiki_restorer, project_tree, avatar_restorer, uploads_restorer].all?(&:restore)
           project_tree.restored_project
         else
           raise Projects::ImportService::Error.new(@shared.errors.join(', '))
diff --git a/lib/gitlab/import_export/merge_request_parser.rb b/lib/gitlab/import_export/merge_request_parser.rb
new file mode 100644
index 00000000000..c20adc20bfd
--- /dev/null
+++ b/lib/gitlab/import_export/merge_request_parser.rb
@@ -0,0 +1,41 @@
+module Gitlab
+  module ImportExport
+    class MergeRequestParser
+      FORKED_PROJECT_ID = -1
+
+      def initialize(project, diff_head_sha, merge_request, relation_hash)
+        @project = project
+        @diff_head_sha = diff_head_sha
+        @merge_request = merge_request
+        @relation_hash = relation_hash
+      end
+
+      def parse!
+        if fork_merge_request? && @diff_head_sha
+          @merge_request.source_project_id = @relation_hash['project_id']
+
+          fetch_ref unless branch_exists?(@merge_request.source_branch)
+          create_target_branch unless branch_exists?(@merge_request.target_branch)
+        end
+
+        @merge_request
+      end
+
+      def create_target_branch
+        @project.repository.create_branch(@merge_request.target_branch, @merge_request.target_branch_sha)
+      end
+
+      def fetch_ref
+        @project.repository.fetch_ref(@project.repository.path, @diff_head_sha, @merge_request.source_branch)
+      end
+
+      def branch_exists?(branch_name)
+        @project.repository.branch_exists?(branch_name)
+      end
+
+      def fork_merge_request?
+        @relation_hash['source_project_id'] == FORKED_PROJECT_ID
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/import_export/project_tree_restorer.rb b/lib/gitlab/import_export/project_tree_restorer.rb
index cda6ddf0443..df21ff22216 100644
--- a/lib/gitlab/import_export/project_tree_restorer.rb
+++ b/lib/gitlab/import_export/project_tree_restorer.rb
@@ -119,7 +119,7 @@ module Gitlab
                                                        relation_hash: parsed_relation_hash(relation_hash),
                                                        members_mapper: members_mapper,
                                                        user: @user,
-                                                       project_id: restored_project.id)
+                                                       project: restored_project)
         end.compact
 
         relation_hash_list.is_a?(Array) ? relation_array : relation_array.first
diff --git a/lib/gitlab/import_export/relation_factory.rb b/lib/gitlab/import_export/relation_factory.rb
index 430de9a1bf8..0545ca10862 100644
--- a/lib/gitlab/import_export/relation_factory.rb
+++ b/lib/gitlab/import_export/relation_factory.rb
@@ -30,11 +30,12 @@ module Gitlab
         new(*args).create
       end
 
-      def initialize(relation_sym:, relation_hash:, members_mapper:, user:, project_id:)
+      def initialize(relation_sym:, relation_hash:, members_mapper:, user:, project:)
         @relation_name = OVERRIDES[relation_sym] || relation_sym
-        @relation_hash = relation_hash.except('noteable_id').merge('project_id' => project_id)
+        @relation_hash = relation_hash.except('noteable_id').merge('project_id' => project.id)
         @members_mapper = members_mapper
         @user = user
+        @project = project
         @imported_object_retries = 0
       end
 
@@ -67,7 +68,7 @@ module Gitlab
         remove_encrypted_attributes!
 
         @relation_hash['data'].deep_symbolize_keys! if @relation_name == :events && @relation_hash['data']
-        set_st_diffs if @relation_name == :merge_request_diff
+        set_st_diff_commits if @relation_name == :merge_request_diff
       end
 
       def update_user_references
@@ -106,6 +107,8 @@ module Gitlab
           imported_object do |object|
             object.commit_id = nil
           end
+        elsif @relation_name == :merge_requests
+          MergeRequestParser.new(@project, @relation_hash.delete('diff_head_sha'), imported_object, @relation_hash).parse!
         else
           imported_object
         end
@@ -116,7 +119,7 @@ module Gitlab
 
         # If source and target are the same, populate them with the new project ID.
         if @relation_hash['source_project_id']
-          @relation_hash['source_project_id'] = same_source_and_target? ? project_id : -1
+          @relation_hash['source_project_id'] = same_source_and_target? ? project_id : MergeRequestParser::FORKED_PROJECT_ID
         end
 
         # project_id may not be part of the export, but we always need to populate it if required.
@@ -167,6 +170,7 @@ module Gitlab
       def imported_object
         yield(existing_or_new_object) if block_given?
         existing_or_new_object.importing = true if existing_or_new_object.respond_to?(:importing)
+
         existing_or_new_object
       rescue ActiveRecord::RecordNotUnique
         # as the operation is not atomic, retry in the unlikely scenario an INSERT is
@@ -189,8 +193,11 @@ module Gitlab
                                                                                relation_class: relation_class)
       end
 
-      def set_st_diffs
+      def set_st_diff_commits
         @relation_hash['st_diffs'] = @relation_hash.delete('utf8_st_diffs')
+
+        HashUtil.deep_symbolize_array!(@relation_hash['st_diffs'])
+        HashUtil.deep_symbolize_array_with_date!(@relation_hash['st_commits'])
       end
 
       def existing_or_new_object
diff --git a/lib/gitlab/ldap/config.rb b/lib/gitlab/ldap/config.rb
index 28129198438..46deea3cc9f 100644
--- a/lib/gitlab/ldap/config.rb
+++ b/lib/gitlab/ldap/config.rb
@@ -124,9 +124,9 @@ module Gitlab
 
       def name_proc
         if allow_username_or_email_login
-          Proc.new { |name| name.gsub(/@.*\z/, '') }
+          proc { |name| name.gsub(/@.*\z/, '') }
         else
-          Proc.new { |name| name }
+          proc { |name| name }
         end
       end
 
diff --git a/lib/gitlab/o_auth/user.rb b/lib/gitlab/o_auth/user.rb
index fcf51b7fc5b..f98481c6d3a 100644
--- a/lib/gitlab/o_auth/user.rb
+++ b/lib/gitlab/o_auth/user.rb
@@ -147,10 +147,8 @@ module Gitlab
       end
 
       def build_new_user
-        user = ::User.new(user_attributes)
-        user.skip_confirmation!
-        user.identities.new(extern_uid: auth_hash.uid, provider: auth_hash.provider)
-        user
+        user_params = user_attributes.merge(extern_uid: auth_hash.uid, provider: auth_hash.provider, skip_confirmation: true)
+        Users::CreateService.new(nil, user_params).build
       end
 
       def user_attributes
diff --git a/lib/gitlab/polling_interval.rb b/lib/gitlab/polling_interval.rb
new file mode 100644
index 00000000000..f0c50584f07
--- /dev/null
+++ b/lib/gitlab/polling_interval.rb
@@ -0,0 +1,22 @@
+module Gitlab
+  class PollingInterval
+    include Gitlab::CurrentSettings
+
+    HEADER_NAME = 'Poll-Interval'.freeze
+
+    def self.set_header(response, interval:)
+      if polling_enabled?
+        multiplier = current_application_settings.polling_interval_multiplier
+        value = (interval * multiplier).to_i
+      else
+        value = -1
+      end
+
+      response.headers[HEADER_NAME] = value.to_s
+    end
+
+    def self.polling_enabled?
+      !current_application_settings.polling_interval_multiplier.zero?
+    end
+  end
+end
diff --git a/lib/gitlab/project_search_results.rb b/lib/gitlab/project_search_results.rb
index db325c00705..0b8959f2fb9 100644
--- a/lib/gitlab/project_search_results.rb
+++ b/lib/gitlab/project_search_results.rb
@@ -62,7 +62,7 @@ module Gitlab
         data << line.sub(ref, '').sub(filename, '').sub(/^:-\d+-/, '').sub(/^::\d+:/, '')
       end
 
-      OpenStruct.new(
+      FoundBlob.new(
         filename: filename,
         basename: basename,
         ref: ref,
diff --git a/lib/gitlab/repo_path.rb b/lib/gitlab/repo_path.rb
new file mode 100644
index 00000000000..4b1d828c45c
--- /dev/null
+++ b/lib/gitlab/repo_path.rb
@@ -0,0 +1,23 @@
+module Gitlab
+  module RepoPath
+    NotFoundError = Class.new(StandardError)
+
+    def self.strip_storage_path(repo_path)
+      result = nil
+
+      Gitlab.config.repositories.storages.values.each do |params|
+        storage_path = params['path']
+        if repo_path.start_with?(storage_path)
+          result = repo_path.sub(storage_path, '')
+          break
+        end
+      end
+
+      if result.nil?
+        raise NotFoundError.new("No known storage path matches #{repo_path.inspect}")
+      end
+
+      result.sub(/\A\/*/, '')
+    end
+  end
+end
diff --git a/lib/gitlab/search_results.rb b/lib/gitlab/search_results.rb
index ccfa517e04b..efe8095beea 100644
--- a/lib/gitlab/search_results.rb
+++ b/lib/gitlab/search_results.rb
@@ -1,5 +1,26 @@
 module Gitlab
   class SearchResults
+    class FoundBlob
+      attr_reader :id, :filename, :basename, :ref, :startline, :data
+
+      def initialize(opts = {})
+        @id = opts.fetch(:id, nil)
+        @filename = opts.fetch(:filename, nil)
+        @basename = opts.fetch(:basename, nil)
+        @ref = opts.fetch(:ref, nil)
+        @startline = opts.fetch(:startline, nil)
+        @data = opts.fetch(:data, nil)
+      end
+
+      def path
+        filename
+      end
+
+      def no_highlighting?
+        false
+      end
+    end
+
     attr_reader :current_user, :query
 
     # Limit search results by passed projects
diff --git a/lib/gitlab/shell.rb b/lib/gitlab/shell.rb
index da8d8ddb8ed..36a871e5bbc 100644
--- a/lib/gitlab/shell.rb
+++ b/lib/gitlab/shell.rb
@@ -35,7 +35,7 @@ module Gitlab
       end
 
       def strip_key(key)
-        key.split(/ /)[0, 2].join(' ')
+        key.split(/[ ]+/)[0, 2].join(' ')
       end
 
       private
@@ -88,6 +88,26 @@ module Gitlab
       true
     end
 
+    # Fetch remote for repository
+    #
+    # name - project path with namespace
+    # remote - remote name
+    # forced - should we use --force flag?
+    # no_tags - should we use --no-tags flag?
+    #
+    # Ex.
+    #   fetch_remote("gitlab/gitlab-ci", "upstream")
+    #
+    def fetch_remote(storage, name, remote, forced: false, no_tags: false)
+      args = [gitlab_shell_projects_path, 'fetch-remote', storage, "#{name}.git", remote, '800']
+      args << '--force' if forced
+      args << '--no-tags' if no_tags
+
+      output, status = Popen.popen(args)
+      raise Error, output unless status.zero?
+      true
+    end
+
     # Move repository
     # storage - project's storage path
     # path - project path with namespace
@@ -174,7 +194,10 @@ module Gitlab
     #   add_namespace("/path/to/storage", "gitlab")
     #
     def add_namespace(storage, name)
-      FileUtils.mkdir_p(full_path(storage, name), mode: 0770) unless exists?(storage, name)
+      path = full_path(storage, name)
+      FileUtils.mkdir_p(path, mode: 0770) unless exists?(storage, name)
+    rescue Errno::EEXIST => e
+      Rails.logger.warn("Directory exists as a file: #{e} at: #{path}")
     end
 
     # Remove directory from repositories storage
diff --git a/lib/gitlab/testing/request_blocker_middleware.rb b/lib/gitlab/testing/request_blocker_middleware.rb
new file mode 100644
index 00000000000..aa67fa08577
--- /dev/null
+++ b/lib/gitlab/testing/request_blocker_middleware.rb
@@ -0,0 +1,61 @@
+# rubocop:disable Style/ClassVars
+
+# This is inspired by http://www.salsify.com/blog/engineering/tearing-capybara-ajax-tests
+# Rack middleware that keeps track of the number of active requests and can block new requests.
+module Gitlab
+  module Testing
+    class RequestBlockerMiddleware
+      @@num_active_requests = Concurrent::AtomicFixnum.new(0)
+      @@block_requests = Concurrent::AtomicBoolean.new(false)
+
+      # Returns the number of requests the server is currently processing.
+      def self.num_active_requests
+        @@num_active_requests.value
+      end
+
+      # Prevents the server from accepting new requests. Any new requests will return an HTTP
+      # 503 status.
+      def self.block_requests!
+        @@block_requests.value = true
+      end
+
+      # Allows the server to accept requests again.
+      def self.allow_requests!
+        @@block_requests.value = false
+      end
+
+      def initialize(app)
+        @app = app
+      end
+
+      def call(env)
+        increment_active_requests
+        if block_requests?
+          block_request(env)
+        else
+          @app.call(env)
+        end
+      ensure
+        decrement_active_requests
+      end
+
+      private
+
+      def block_requests?
+        @@block_requests.true?
+      end
+
+      def block_request(env)
+        [503, {}, []]
+      end
+
+      def increment_active_requests
+        @@num_active_requests.increment
+      end
+
+      def decrement_active_requests
+        @@num_active_requests.decrement
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/uploads_transfer.rb b/lib/gitlab/uploads_transfer.rb
index 81701831a6a..7d0c47c5361 100644
--- a/lib/gitlab/uploads_transfer.rb
+++ b/lib/gitlab/uploads_transfer.rb
@@ -1,7 +1,7 @@
 module Gitlab
   class UploadsTransfer < ProjectTransfer
     def root_dir
-      File.join(Rails.root, "public", "uploads")
+      File.join(CarrierWave.root, GitlabUploader.base_dir)
     end
   end
 end
diff --git a/lib/gitlab/url_sanitizer.rb b/lib/gitlab/url_sanitizer.rb
index c81dc7e30d0..9ce13feb79a 100644
--- a/lib/gitlab/url_sanitizer.rb
+++ b/lib/gitlab/url_sanitizer.rb
@@ -18,6 +18,12 @@ module Gitlab
       false
     end
 
+    def self.http_credentials_for_user(user)
+      return {} unless user.respond_to?(:username)
+
+      { user: user.username }
+    end
+
     def initialize(url, credentials: nil)
       @url = Addressable::URI.parse(url.strip)
       @credentials = credentials
diff --git a/lib/gitlab/workhorse.rb b/lib/gitlab/workhorse.rb
index eae1a0abf06..a8a7bf9bc12 100644
--- a/lib/gitlab/workhorse.rb
+++ b/lib/gitlab/workhorse.rb
@@ -1,6 +1,7 @@
 require 'base64'
 require 'json'
 require 'securerandom'
+require 'uri'
 
 module Gitlab
   class Workhorse
@@ -15,16 +16,37 @@ module Gitlab
     SECRET_LENGTH = 32
 
     class << self
-      def git_http_ok(repository, user)
+      def git_http_ok(repository, user, action)
+        repo_path = repository.path_to_repo
         params = {
           GL_ID: Gitlab::GlId.gl_id(user),
-          RepoPath: repository.path_to_repo,
+          RepoPath: repo_path,
         }
 
-        params.merge!(
-          GitalySocketPath: Gitlab.config.gitaly.socket_path,
-          GitalyResourcePath: "/projects/#{repository.project.id}/git-http/info-refs",
-        ) if Gitlab.config.gitaly.socket_path.present?
+        if Gitlab.config.gitaly.enabled
+          storage = repository.project.repository_storage
+          address = Gitlab::GitalyClient.get_address(storage)
+          # TODO: use GitalyClient code to assemble the Repository message
+          params[:Repository] = Gitaly::Repository.new(
+            path: repo_path,
+            storage_name: storage,
+            relative_path: Gitlab::RepoPath.strip_storage_path(repo_path),
+          ).to_h
+
+          feature_enabled = case action.to_s
+                            when 'git_receive_pack'
+                              # Disabled for now, see https://gitlab.com/gitlab-org/gitaly/issues/172
+                              false
+                            when 'git_upload_pack'
+                              Gitlab::GitalyClient.feature_enabled?(:post_upload_pack)
+                            when 'info_refs'
+                              true
+                            else
+                              raise "Unsupported action: #{action}"
+                            end
+
+          params[:GitalyAddress] = address if feature_enabled
+        end
 
         params
       end