Allow access to the wiki with git when repository feature disabled

app/policies/project_policy.rb

@@ -50,6 +50,7 @@ class ProjectPolicy < BasePolicy
 
   def reporter_access!
     can! :download_code
+    can! :download_wiki_code
     can! :fork_project
     can! :create_project_snippet
     can! :update_issue
@@ -187,6 +188,7 @@ class ProjectPolicy < BasePolicy
 
     unless project.feature_available?(:wiki, user) || project.has_external_wiki?
       cannot!(*named_abilities(:wiki))
+      cannot!(:download_wiki_code)
     end
 
     unless project.feature_available?(:builds, user) && repository_enabled
@@ -226,6 +228,7 @@ class ProjectPolicy < BasePolicy
     can! :read_commit_status
     can! :read_container_image
     can! :download_code
+    can! :download_wiki_code
     can! :read_cycle_analytics
 
     # NOTE: may be overridden by IssuePolicy

lib/gitlab/git_access.rb

@@ -46,7 +46,7 @@ module Gitlab
     def download_access_check
       if user
         user_download_access_check
-      elsif deploy_key.nil? && !Guest.can?(:download_code, project)
+      elsif deploy_key.nil? && !guest_can_downlod_code?
         raise UnauthorizedError, ERROR_MESSAGES[:download]
       end
     end
@@ -59,6 +59,10 @@ module Gitlab
       end
     end
 
+    def guest_can_downlod_code?
+      Guest.can?(:download_code, project)
+    end
+
     def user_download_access_check
       unless user_can_download_code? || build_can_download_code?
         raise UnauthorizedError, ERROR_MESSAGES[:download]

lib/gitlab/git_access_wiki.rb

 module Gitlab
   class GitAccessWiki < GitAccess
+    def guest_can_downlod_code?
+      Guest.can?(:download_wiki_code, project)
+    end
+
+    def user_can_download_code?
+      authentication_abilities.include?(:download_code) && user_access.can_do_action?(:download_wiki_code)
+    end
+
     def change_access_check(change)
       if user_access.can_do_action?(:create_wiki)
         build_status_object(true)