Redirect commits to root_ref if no ref is provided

app/controllers/application_controller.rb

@@ -63,6 +63,10 @@ class ApplicationController < ActionController::Base
     render_503
   end
 
+  def redirect_commits_root
+    redirect_to :controller => 'commits', :action => 'show', :id => @repository.root_ref
+  end
+
   def redirect_back_or_default(default: root_path, options: {})
     redirect_to request.referer.present? ? :back : default, options
   end

changelogs/unreleased/31576-redirect-commits-to-root-if-no-ref.yml

@@ -0,0 +1,5 @@
+---
+title: Redirect commits to root if no ref is provided (31576)
+merge_request: 
+author: Kia Mei Somabes
+type: added

config/routes/repository.rb

@@ -83,6 +83,7 @@ scope format: false do
     get '/raw/*id', to: 'raw#show', as: :raw
     get '/blame/*id', to: 'blame#show', as: :blame
 
+    get '/commits/', to: 'application#redirect_commits_root', as: :commits_root
     get '/commits/*id/signatures', to: 'commits#signatures', as: :signatures
     get '/commits/*id', to: 'commits#show', as: :commits