Merge branch '17464-backport-email-syntax-highlighting' into 'master'

Syntax-highlight diffs in push emails

![image](/uploads/8ecbabc65382214b8de63aae24f66cea/image.png)

Based on:
https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/151



See merge request !4147

1 files changed, 6 insertions, 1 deletions

diff --git a/lib/gitlab/email/message/repository_push.rb b/lib/gitlab/email/message/repository_push.rb
index 2c91a0487c3..e2fee6b9f3e 100644
--- a/lib/gitlab/email/message/repository_push.rb
+++ b/lib/gitlab/email/message/repository_push.rb
@@ -5,6 +5,7 @@ module Gitlab
         attr_reader :author_id, :ref, :action
 
         include Gitlab::Routing.url_helpers
+        include DiffHelper
 
         delegate :namespace, :name_with_namespace, to: :project, prefix: :project
         delegate :name, to: :author, prefix: :author
@@ -36,7 +37,7 @@ module Gitlab
         end
 
         def diffs
-          @diffs ||= (compare.diffs if compare)
+          @diffs ||= (safe_diff_files(compare.diffs, diff_refs) if compare)
         end
 
         def diffs_count
@@ -47,6 +48,10 @@ module Gitlab
           @opts[:compare]
         end
 
+        def diff_refs
+          @opts[:diff_refs]
+        end
+
         def compare_timeout
           diffs.overflow? if diffs
         end