Merge branch 'escape-file-extension' into 'master'

Escape file extension when parsing search results

When a file extension contains characters which have a meaning in regular expressions, the search may crash.

Fixes #18553 

See merge request !5141

CHANGELOG

@@ -8,6 +8,7 @@ v 8.10.0 (unreleased)
   - Wrap code blocks on Activies and Todos page. !4783 (winniehell)
   - Align flash messages with left side of page content !4959 (winniehell)
   - Display last commit of deleted branch in push events !4699 (winniehell)
+  - Escape file extension when parsing search results !5141 (winniehell)
   - Apply the trusted_proxies config to the rack request object for use with rack_attack
   - Add Sidekiq queue duration to transaction metrics.
   - Add a new column `artifacts_size` to table `ci_builds` !4964

app/models/repository.rb

@@ -911,7 +911,7 @@ class Repository
       if line =~ /^.*:.*:\d+:/
         ref, filename, startline = line.split(':')
         startline = startline.to_i - index
-        extname = File.extname(filename)
+        extname = Regexp.escape(File.extname(filename))
         basename = filename.sub(/#{extname}$/, '')
         break
       end