1 files changed, 31 insertions, 5 deletions
diff --git a/lib/gitlab/conflict/file.rb b/lib/gitlab/conflict/file.rb
index 30911b49b18..501c2111530 100644
--- a/lib/gitlab/conflict/file.rb
+++ b/lib/gitlab/conflict/file.rb
@@ -3,6 +3,7 @@ module Gitlab
     class File
       include Gitlab::Routing
       include IconsHelper
+      include Gitlab::Utils::StrongMemoize
 
       CONTEXT_LINES = 3
 
@@ -30,11 +31,8 @@ module Gitlab
       end
 
       def highlight_lines!
-        their_file = lines.reject { |line| line.type == 'new' }.map(&:text).join("\n")
-        our_file = lines.reject { |line| line.type == 'old' }.map(&:text).join("\n")
-
-        their_highlight = Gitlab::Highlight.highlight(their_path, their_file, repository: repository).lines
-        our_highlight = Gitlab::Highlight.highlight(our_path, our_file, repository: repository).lines
+        their_highlight = Gitlab::Highlight.highlight(their_path, their_lines, language: their_language).lines
+        our_highlight = Gitlab::Highlight.highlight(our_path, our_lines, language: our_language).lines
 
         lines.each do |line|
           line.rich_text =
@@ -182,6 +180,34 @@ module Gitlab
             raw_line[:line_new], parent_file: self)
         end
       end
+
+      def their_language
+        strong_memoize(:their_language) do
+          repository.gitattribute(their_path, 'gitlab-language')
+        end
+      end
+
+      def our_language
+        strong_memoize(:our_language) do
+          if our_path == their_path
+            their_language
+          else
+            repository.gitattribute(our_path, 'gitlab-language')
+          end
+        end
+      end
+
+      def their_lines
+        strong_memoize(:their_lines) do
+          lines.reject { |line| line.type == 'new' }.map(&:text).join("\n")
+        end
+      end
+
+      def our_lines
+        strong_memoize(:our_lines) do
+          lines.reject { |line| line.type == 'old' }.map(&:text).join("\n")
+        end
+      end
     end
   end
 end