redirect to new files with the same path as deleted files

Change-Id: I7b5e9736bc06901dde4f16a493f15e5c5f5124ae
Reviewed-on: https://gerrit.instructure.com/5038
Tested-by: Hudson <hudson@instructure.com>
Reviewed-by: Brian Palmer <brianp@instructure.com>
Reviewed-by: Brian Whitmer <brian@instructure.com>

app/controllers/files_controller.rb

@@ -158,6 +158,7 @@ class FilesController < ApplicationController
   end
   
   def show
+    original_params = params.dup
     params[:id] ||= params[:file_id]
     get_context
     if @context && !@context.is_a?(User)
@@ -171,6 +172,13 @@ class FilesController < ApplicationController
     @context = UserProfile.new(@context) if @context == @current_user
     add_crumb(t('#crumbs.files', "Files"), named_context_url(@context, :context_files_url)) unless @skip_crumb
     if @attachment.deleted?
+      # before telling them it's deleted, try to find another active attachment with the same full path
+      if new_attachment = Folder.find_attachment_in_context_with_path(@context, @attachment.full_display_path)
+        original_params[:id] = new_attachment.id
+        redirect_to original_params
+        return
+      end
+      
       flash[:notice] = t 'notices.deleted', "The file %{display_name} has been deleted", :display_name => @attachment.display_name
       if params[:preview] && @attachment.mime_class == 'image'
         redirect_to '/images/blank.png'
@@ -255,17 +263,7 @@ class FilesController < ApplicationController
       end
     end
 
-    if !@attachment
-      # The relative path is for a different file, try to find it
-      components = path.split('/')
-      component = components.shift
-      @context.folders.active.find_all_by_parent_folder_id(nil).each do |folder|
-        if folder.name == component
-          @attachment = folder.find_attachment_with_components(components.dup)
-          break if @attachment
-        end
-      end
-    end
+    @attachment ||= Folder.find_attachment_in_context_with_path(@context, path)
 
     raise ActiveRecord::RecordNotFound if !@attachment
     params[:id] = @attachment.id

app/models/folder.rb

@@ -291,6 +291,18 @@ class Folder < ActiveRecord::Base
     end
   end
 
+  def self.find_attachment_in_context_with_path(context, path)
+    components = path.split('/')
+    component = components.shift
+    context.folders.active.find_all_by_parent_folder_id(nil).each do |folder|
+      if folder.name == component
+        attachment = folder.find_attachment_with_components(components.dup)
+        return attachment if attachment
+      end
+    end
+    nil
+  end
+
   def find_attachment_with_components(components)
     component = components.shift
     if components.empty?

spec/controllers/files_controller_spec.rb

@@ -253,6 +253,22 @@ describe FilesController do
       @module.evaluate_for(@user, true, true).state.should eql(:unlocked)
     end
 
+    it "should redirect to an existing attachment with the same path as a deleted attachment" do
+      course_with_student_logged_in(:active_all => true)
+      old_file = course_file
+      old_file.display_name = 'holla'
+      old_file.save
+      old_file.destroy
+      
+      new_file = course_file
+      new_file.display_name = 'holla'
+      new_file.save
+      
+      get 'show', :course_id => @course.id, :id => old_file.id
+      response.should be_redirect
+      response.redirected_to['id'].should == new_file.id
+    end
+
   end
 
   describe "GET 'show_relative'" do