From 0267e4e3d761f3cab8d5fb3b373c41e9742aebef Mon Sep 17 00:00:00 2001
From: evazion <noizave@gmail.com>
Date: Mon, 12 Sep 2022 21:16:52 -0500
Subject: [PATCH] wikis: fix exception when wiki doesn't have a tag.

Fix a nil reference exception in the sidebar when a wiki page doesn't
belong to a tag.

Also hide the options sidebar on the new wiki page since none of the
options are relevant when creating a new wiki.
---
 app/views/wiki_pages/_sidebar.html.erb        | 24 ++++++++++++++-----
 test/functional/wiki_pages_controller_test.rb |  8 +++++++
 2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/app/views/wiki_pages/_sidebar.html.erb b/app/views/wiki_pages/_sidebar.html.erb
index f846b6300..3640570ab 100644
--- a/app/views/wiki_pages/_sidebar.html.erb
+++ b/app/views/wiki_pages/_sidebar.html.erb
@@ -2,19 +2,31 @@
   <%= render "posts/partials/index/blacklist" %>
   <%= render "wiki_pages/recent_changes" %>
 
-  <% if @wiki_page.present? %>
+  <% if @wiki_page.present? && !@wiki_page.new_record? %>
     <h2>Options</h2>
 
     <ul>
       <% unless @wiki_page.is_meta_wiki? %>
-        <li><%= link_to "Tag History", tag_versions_path(search: { tag_id: @wiki_page.tag.id }) %></li>
-        <li><%= link_to "Post History", post_versions_path(search: { changed_tags: @wiki_page.title }) %></li>
+        <% if @wiki_page.tag.present? %>
+          <li><%= link_to "Tag History", tag_versions_path(search: { tag_id: @wiki_page.tag&.id }) %></li>
+        <% end %>
+
+        <% if @wiki_page.title.present? %>
+          <li><%= link_to "Post History", post_versions_path(search: { changed_tags: @wiki_page.title }) %></li>
+        <% end %>
       <% end %>
-      <li><%= link_to "Wiki History", wiki_page_versions_path(search: { wiki_page_id: @wiki_page.id }) %></li>
-      <% if Danbooru.config.forum_enabled?.to_s.truthy? %>
+
+      <% if @wiki_page.id.present? %>
+        <li><%= link_to "Wiki History", wiki_page_versions_path(search: { wiki_page_id: @wiki_page.id }) %></li>
+      <% end %>
+
+      <% if Danbooru.config.forum_enabled?.to_s.truthy? && @wiki_page.title.present? %>
         <li><%= link_to "Discussions", forum_posts_path(search: { linked_to: @wiki_page.title }) %></li>
       <% end %>
-      <li><%= link_to "What Links Here", wiki_pages_path(search: { linked_to: @wiki_page.title }) %></li>
+
+      <% if @wiki_page.title.present? %>
+        <li><%= link_to "What Links Here", wiki_pages_path(search: { linked_to: @wiki_page.title }) %></li>
+      <% end %>
     </ul>
   <% end %>
 <% end %>
diff --git a/test/functional/wiki_pages_controller_test.rb b/test/functional/wiki_pages_controller_test.rb
index 3fdeb990b..7bd57cb2f 100644
--- a/test/functional/wiki_pages_controller_test.rb
+++ b/test/functional/wiki_pages_controller_test.rb
@@ -97,6 +97,14 @@ class WikiPagesControllerTest < ActionDispatch::IntegrationTest
         assert_response :success
       end
 
+      should "render for a wiki without a tag" do
+        @wiki_page = create(:wiki_page, title: "help:foo")
+        get wiki_page_path(@wiki_page)
+
+        assert(@wiki_page.tag.nil?)
+        assert_response :success
+      end
+
       should "show the 'does not exist' page for a nonexistent title" do
         get wiki_page_path("what")