Fix 404s when C++ .gitignore template selected

Due to a overly-stringent regex, the project template API was 404'ing
when C++ was requested as the template. Loosen the regex to allow `+`
and `%` for URL-encoded characters.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/57857

1 files changed, 4 insertions, 1 deletions

diff --git a/lib/api/project_templates.rb b/lib/api/project_templates.rb
index d05ddad7466..119902a189c 100644
--- a/lib/api/project_templates.rb
+++ b/lib/api/project_templates.rb
@@ -36,7 +36,10 @@ module API
         optional :project, type: String, desc: 'The project name to use when expanding placeholders in the template. Only affects licenses'
         optional :fullname, type: String, desc: 'The full name of the copyright holder to use when expanding placeholders in the template. Only affects licenses'
       end
-      get ':id/templates/:type/:name', requirements: { name: /[\w\.-]+/ } do
+      # The regex is needed to ensure a period (e.g. agpl-3.0)
+      # isn't confused with a format type. We also need to allow encoded
+      # values (e.g. C%2B%2B for C++), so allow % and + as well.
+      get ':id/templates/:type/:name', requirements: { name: /[\w%.+-]+/ } do
         template = TemplateFinder
           .build(params[:type], user_project, name: params[:name])
           .execute