Fix #4405: Post version table css doesn't keep ratio at smaller resolutions.

Bug: extremely long sources cause the Tags column to become extremely
wide. Caused by the source link not having the word-break property set.

Fix: use post_source_tag, which lets the `a[rel=external] { word-break: break-word; }`
rule take effect.

Example: https://danbooru.donmai.us/post_versions?search%5Bpost_id%5D=3809742

app/helpers/posts_helper.rb

@@ -42,12 +42,12 @@ module PostsHelper
     verifier.generate("#{value},#{session[:session_id]}")
   end
 
-  def post_source_tag(post)
+  def post_source_tag(source, normalized_source = source)
     # Only allow http:// and https:// links. Disallow javascript: links.
-    if post.source =~ %r!\Ahttps?://!i
-      external_link_to(post.normalized_source, strip: :subdomain) + " ".html_safe + link_to("»", post.source, rel: "external noreferrer nofollow")
+    if source =~ %r!\Ahttps?://!i
+      external_link_to(normalized_source, strip: :subdomain) + " ".html_safe + link_to("»", source, rel: "external noreferrer nofollow")
     else
-      post.source
+      source
     end
   end
 

app/views/modqueue/_post.html.erb

@@ -40,7 +40,7 @@
     <div class="row">
       <span class="info">
         <strong>Source</strong>
-        <%= post_source_tag(post) %>
+        <%= post_source_tag(post.source, post.normalized_source) %>
       </span>
     </div>
 

app/views/post_versions/_listing.html.erb

@@ -24,7 +24,7 @@
         </div>
         <div><b>Tags:</b> <%= TagSetPresenter.new(post_version.tag_array).inline_tag_list_html %></div>
         <div>
-          <%= post_version_field(post_version, :source) %>
+          <%= post_source_tag(post_version.source) %>
         </div>
       <% end %>
       <% t.column "Edits", td: {class: "col-expand"}, width: "40%" do |post_version| %>

app/views/posts/partials/show/_information.html.erb

@@ -22,7 +22,7 @@
       (<span itemprop="width"><%= post.image_width %></span>x<span itemprop="height"><%= post.image_height %></span>)
     <% end %>
   </li>
-  <li id="post-info-source">Source: <%= post_source_tag(post) %></li>
+  <li id="post-info-source">Source: <%= post_source_tag(post.source, post.normalized_source) %></li>
   <li id="post-info-rating">Rating: <%= post.pretty_rating %></li>
   <li id="post-info-score">Score: <span id="score-for-post-<%= post.id %>"><%= post.score %></span>
     <% if policy(PostVote).create? %>