Fix WikiPage#title_changed for paths with spaces

If a wiki page is inside a directory with spaces, the change detection
didn't account for hyphenated spaces and mistakenly assumed the title
was changed when it wasn't, causing a validation error.

This also fixes the specs to catch this case.

app/models/wiki_page.rb

@@ -257,7 +257,7 @@ class WikiPage
   def title_changed?
     if persisted?
       old_title, old_dir = wiki.page_title_and_dir(self.class.unhyphenize(@page.url_path))
-      new_title, new_dir = wiki.page_title_and_dir(title)
+      new_title, new_dir = wiki.page_title_and_dir(self.class.unhyphenize(title))
 
       new_title != old_title || (title.include?('/') && new_dir != old_dir)
     else

changelogs/unreleased/209761-fix-wiki-directories-with-hyphens.yml

+---
+title: Fix WikiPage#title_changed for paths with spaces
+merge_request: 27087
+author:
+type: fixed

spec/models/wiki_page_spec.rb

@@ -480,8 +480,8 @@ describe WikiPage do
 
     let(:untitled_page) { described_class.new(wiki) }
     let(:directory_page) do
-      create_page('parent/child', 'test content')
-      wiki.find_page('parent/child')
+      create_page('parent directory/child page', 'test content')
+      wiki.find_page('parent directory/child page')
     end
 
     where(:page, :title, :changed) do
@@ -494,15 +494,25 @@ describe WikiPage do
 
       :existing_page  | nil                             | false
       :existing_page  | 'test page'                     | false
+      :existing_page  | 'test-page'                     | false
       :existing_page  | '/test page'                    | false
+      :existing_page  | '/test-page'                    | false
+      :existing_page  | ' test page '                   | true
       :existing_page  | 'new title'                     | true
+      :existing_page  | 'new-title'                     | true
 
       :directory_page | nil                             | false
-      :directory_page | 'parent/child' | false
-      :directory_page | 'child'        | false
-      :directory_page | '/child'       | true
-      :directory_page | 'parent/other' | true
-      :directory_page | 'other/child'  | true
+      :directory_page | 'parent directory/child page'   | false
+      :directory_page | 'parent-directory/child page'   | false
+      :directory_page | 'parent-directory/child-page'   | false
+      :directory_page | 'child page'                    | false
+      :directory_page | 'child-page'                    | false
+      :directory_page | '/child page'                   | true
+      :directory_page | 'parent directory/other'        | true
+      :directory_page | 'parent-directory/other'        | true
+      :directory_page | 'parent-directory / child-page' | true
+      :directory_page | 'other directory/child page'    | true
+      :directory_page | 'other-directory/child page'    | true
     end
 
     with_them do