fixes #1829

app/controllers/posts_controller.rb

@@ -9,6 +9,10 @@ class PostsController < ApplicationController
   rescue_from ActiveRecord::RecordNotFound, :with => :rescue_exception
 
   def index
+    if params[:md5].present?
+      @post = Post.find_by_md5(params[:md5])
+      redirect_to post_path(@post)
+    else
       @post_set = PostSets::Post.new(tag_query, params[:page], params[:limit] || CurrentUser.user.per_page, params[:raw])
       @posts = @post_set.posts
       respond_with(@posts) do |format|
@@ -18,6 +22,7 @@ class PostsController < ApplicationController
         end
       end
     end
+  end
 
   def show
     @post = Post.find(params[:id])

config/routes.rb

@@ -309,6 +309,7 @@ Danbooru::Application.routes.draw do
   match "/post/popular_by_month" => redirect("/explore/posts/popular")
   match "/post/show/:id/:tag_title" => redirect("/posts/%{id}")
   match "/post/show/:id" => redirect("/posts/%{id}")
+  match "/post/show" => redirect {|params, req| "/posts?md5=#{req.params[:md5]}"}
   match "/post/view/:id/:tag_title" => redirect("/posts/%{id}")
   match "/post/view/:id" => redirect("/posts/%{id}")
   match "/post/flag/:id" => redirect("/posts/%{id}")