Fix links to uploaded files on wiki pages

changelogs/unreleased/42031-fix-links-to-uploads-in-wikis.yml

+---
+title: Fix links to uploaded files on wiki pages
+merge_request: 16499
+author:
+type: fixed

lib/banzai/filter/wiki_link_filter/rewriter.rb

@@ -9,6 +9,10 @@ module Banzai
         end
 
         def apply_rules
+          # Special case: relative URLs beginning with `/uploads/` refer to
+          # user-uploaded files and will be handled elsewhere.
+          return @uri.to_s if @uri.relative? && @uri.path.starts_with?('/uploads/')
+
           apply_file_link_rules!
           apply_hierarchical_link_rules!
           apply_relative_link_rules!

spec/lib/banzai/filter/wiki_link_filter_spec.rb

@@ -10,15 +10,23 @@ describe Banzai::Filter::WikiLinkFilter do
 
   it "doesn't rewrite absolute links" do
     filtered_link = filter("<a href='http://example.com:8000/'>Link</a>", project_wiki: wiki).children[0]
+
     expect(filtered_link.attribute('href').value).to eq('http://example.com:8000/')
   end
 
+  it "doesn't rewrite links to project uploads" do
+    filtered_link = filter("<a href='/uploads/a.test'>Link</a>", project_wiki: wiki).children[0]
+
+    expect(filtered_link.attribute('href').value).to eq('/uploads/a.test')
+  end
+
   describe "invalid links" do
     invalid_links = ["http://:8080", "http://", "http://:8080/path"]
 
     invalid_links.each do |invalid_link|
       it "doesn't rewrite invalid invalid_links like #{invalid_link}" do
         filtered_link = filter("<a href='#{invalid_link}'>Link</a>", project_wiki: wiki).children[0]
+
         expect(filtered_link.attribute('href').value).to eq(invalid_link)
       end
     end