Merge branch 'revert-4026' into 'master'

Revert "Merge branch 'wiki-fix' into 'master'"

This reverts commit 4cc85a58e8 (!4026), reversing
changes made to 90ae445ba9.

From https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4026#note_11719950:

>  1. On Ruby 2.1.x, the [`uri.path = ::File.join(project_wiki_base_path, uri.path)`](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/lib/banzai/filter/wiki_link_filter.rb#L39) raises an `URI::InvalidComponentError: bad component(expected relative path component): http://bar.com/baz` error in `Banzai::Filter::WikiLinkFilter#rebuild_wiki_uri`, which is then rescued in [`Banzai::Filter::WikiLinkFilter#process_link_attr`](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/lib/banzai/filter/wiki_link_filter.rb#L34), thus the link is not modified and the tests pass.
1. On Ruby 2.2.x, the same line doesn't raise an error anymore, thus tests are broken on Ruby 2.2 only. I didn't really understand yet why having absolute links in the wiki would break some tests vs having relative links as before, but I think the safest course to action is to revert this MR and to find another fix (probably just prepending `ProjectWiki#wiki_base_path` with the relative URL path component if we are in the case of a relative URL...
/cc @artem-sidorenko

Just a FYI note: no need to pick into `8-7-stable` since the original commit was not picked.

See merge request !4105

CHANGELOG

@@ -39,7 +39,6 @@ v 8.8.0 (unreleased)
 
 v 8.7.4
   - Fix always showing build notification message when switching between merge requests
-  - Fix links on wiki pages for relative url setups. !4026 (Artem Sidorenko)
   - Links for Redmine issue references are generated correctly again (Benedikt Huss)
 
 v 8.7.3

app/models/project_wiki.rb

@@ -40,7 +40,7 @@ class ProjectWiki
   end
 
   def wiki_base_path
-    [Gitlab.config.gitlab.url, "/", @project.path_with_namespace, "/wikis"].join('')
+    ["/", @project.path_with_namespace, "/wikis"].join('')
   end
 
   # Returns the Gollum::Wiki object.

lib/gitlab/url_builder.rb

@@ -62,7 +62,7 @@ module Gitlab
     end
 
     def wiki_page_url
-      "#{object.wiki.wiki_base_path}/#{object.slug}"
+      "#{Gitlab.config.gitlab.url}#{object.wiki.wiki_base_path}/#{object.slug}"
     end
   end
 end

spec/lib/gitlab/url_builder_spec.rb

@@ -112,7 +112,7 @@ describe Gitlab::UrlBuilder, lib: true do
         wiki_page = build(:wiki_page)
         url = described_class.build(wiki_page)
 
-        expect(url).to eq "#{Gitlab.config.gitlab.url}/#{wiki_page.wiki.project.path_with_namespace}/wikis/#{wiki_page.slug}"
+        expect(url).to eq "#{Gitlab.config.gitlab.url}#{wiki_page.wiki.wiki_base_path}/#{wiki_page.slug}"
       end
     end
   end

spec/models/project_wiki_spec.rb

@@ -38,9 +38,7 @@ describe ProjectWiki, models: true do
 
   describe "#wiki_base_path" do
     it "returns the wiki base path" do
-      gitlab_url = Gitlab.config.gitlab.url
-      wiki_base_path = "#{gitlab_url}/#{project.path_with_namespace}/wikis"
-
+      wiki_base_path = "/#{project.path_with_namespace}/wikis"
       expect(subject.wiki_base_path).to eq(wiki_base_path)
     end
   end