Fix #4193: Wiki tags for related tags are no longer in wiki order.

app/models/wiki_page.rb

@@ -206,8 +206,9 @@ class WikiPage < ApplicationRecord
   end
 
   def tags
-    titles = DText.parse_wiki_titles(body)
+    titles = DText.parse_wiki_titles(body).uniq
-    Tag.nonempty.where(name: titles.uniq).pluck(:name)
+    tags = Tag.nonempty.where(name: titles).pluck(:name)
+    titles & tags
   end
 
   def visible?

test/unit/related_tag_query_test.rb

@@ -91,6 +91,13 @@ class RelatedTagQueryTest < ActiveSupport::TestCase
       should "find any tags embedded in the wiki page" do
         assert_equal(["bbb", "ccc"], @query.wiki_page_tags)
       end
+
+      should "return the tags in the same order as given by the wiki" do
+        create(:wiki_page, title: "wiki", body: "[[ccc]] [[bbb]] [[ccc]] [[bbb]] [[aaa]]")
+
+        query = RelatedTagQuery.new(query: "wiki")
+        assert_equal(%w[ccc bbb aaa], query.wiki_page_tags)
+      end
     end
   end