diff --git a/app/controllers/repositories_controller.rb b/app/controllers/repositories_controller.rb
index 85b421e775..e322ea49a8 100644
--- a/app/controllers/repositories_controller.rb
+++ b/app/controllers/repositories_controller.rb
@@ -257,12 +257,13 @@ class RepositoriesController < ApplicationController
                       Digest::MD5.hexdigest("#{@path}-#{@rev}-#{@rev_to}-#{@diff_type}-#{current_language}")
       unless read_fragment(@cache_key)
         @diff = @repository.diff(@path, @rev, @rev_to)
-        show_error_not_found unless @diff
+        (show_error_not_found; return) unless @diff
       end
 
       @changeset = @repository.find_changeset_by_name(@rev)
       @changeset_to = @rev_to ? @repository.find_changeset_by_name(@rev_to) : nil
       @diff_format_revisions = @repository.diff_format_revisions(@changeset, @changeset_to)
+      render :diff, :formats => :html
     end
   end
 
diff --git a/config/routes.rb b/config/routes.rb
index 3c1fd02561..dd951a4007 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -249,22 +249,31 @@ Rails.application.routes.draw do
   post   'projects/:id/repository/:repository_id/revisions/:rev/issues', :to => 'repositories#add_related_issue'
   delete 'projects/:id/repository/:repository_id/revisions/:rev/issues/:issue_id', :to => 'repositories#remove_related_issue'
   get 'projects/:id/repository/:repository_id/revisions', :to => 'repositories#revisions'
-  %w(browse show entry raw annotate diff).each do |action|
+  %w(browse show entry raw annotate).each do |action|
     get "projects/:id/repository/:repository_id/revisions/:rev/#{action}(/*path)",
         :controller => 'repositories',
         :action => action,
-        :format => false,
+        :format => 'html',
         :constraints => {:rev => /[a-z0-9\.\-_]+/, :path => /.*/}
   end
 
-  %w(browse entry raw changes annotate diff).each do |action|
+  %w(browse entry raw changes annotate).each do |action|
     get "projects/:id/repository/:repository_id/#{action}(/*path)",
         :controller => 'repositories',
         :action => action,
-        :format => false,
+        :format => 'html',
         :constraints => {:path => /.*/}
   end
 
+  get "projects/:id/repository/:repository_id/revisions/:rev/diff(/*path)",
+      :to => 'repositories#diff',
+      :format => false,
+      :constraints => {:rev => /[a-z0-9\.\-_]+/, :path => /.*/}
+  get "projects/:id/repository/:repository_id/diff(/*path)",
+      :to => 'repositories#diff',
+      :format => false,
+      :constraints => {:path => /.*/}
+
   get 'projects/:id/repository/:repository_id/show/*path', :to => 'repositories#show', :format => 'html', :constraints => {:path => /.*/}
 
   get 'projects/:id/repository/:repository_id', :to => 'repositories#show', :path => nil
diff --git a/test/integration/repositories_git_test.rb b/test/integration/repositories_git_test.rb
index 862b779bb1..d677f9e5b5 100644
--- a/test/integration/repositories_git_test.rb
+++ b/test/integration/repositories_git_test.rb
@@ -78,6 +78,20 @@ class RepositoriesGitTest < Redmine::IntegrationTest
       assert_match /\Acommit deff712f05a90d96edbd70facc47d944be5897e3/, response.body
     end
 
+    def test_get_diff_with_format_text_should_return_html
+      @repository.fetch_changesets
+      assert_equal NUM_REV, @repository.changesets.count
+
+      get "/projects/subproject1/repository/#{@repository.id}/revisions/deff712f05a90d96edbd70facc47d944be5897e3/diff/sources/watchers_controller.rb", :params => { :format => 'txt' }
+      assert_response :success
+
+      assert a = css_select("a.diff").first
+      assert_equal 'Unified diff', a.text
+      get a['href']
+      assert_response :success
+      assert_match /\Acommit deff712f05a90d96edbd70facc47d944be5897e3/, response.body
+    end
+
   else
     puts "Git test repository NOT FOUND. Skipping integration tests !!!"
     def test_fake; assert true end
diff --git a/test/integration/routing/repositories_test.rb b/test/integration/routing/repositories_test.rb
index eeb927e75b..e2a6c6f67e 100644
--- a/test/integration/routing/repositories_test.rb
+++ b/test/integration/routing/repositories_test.rb
@@ -53,26 +53,34 @@ class RoutingRepositoriesTest < Redmine::RoutingTest
     should_route 'GET /projects/foo/repository/foo/revisions.atom' => 'repositories#revisions', :id => 'foo', :repository_id => 'foo', :format => 'atom'
 
     should_route 'GET /projects/foo/repository/foo/revisions/2457' => 'repositories#revision', :id => 'foo', :repository_id => 'foo', :rev => '2457'
-    should_route 'GET /projects/foo/repository/foo/revisions/2457/show' => 'repositories#show', :id => 'foo', :repository_id => 'foo', :rev => '2457'
+    should_route 'GET /projects/foo/repository/foo/revisions/2457/show' => 'repositories#show', :id => 'foo', :repository_id => 'foo', :rev => '2457', :format => 'html'
     should_route 'GET /projects/foo/repository/foo/revisions/2457/diff' => 'repositories#diff', :id => 'foo', :repository_id => 'foo', :rev => '2457'
 
-    %w(show diff entry raw annotate).each do |action|
+    %w(show entry raw annotate).each do |action|
       @paths.each do |path|
         should_route "GET /projects/foo/repository/foo/revisions/2457/#{action}/#{path}" => "repositories##{action}",
-          :id => 'foo', :repository_id => 'foo', :rev => '2457', :path => path
+          :id => 'foo', :repository_id => 'foo', :rev => '2457', :path => path, :format => 'html'
       end
     end
+    @paths.each do |path|
+      should_route "GET /projects/foo/repository/foo/revisions/2457/diff/#{path}" => "repositories#diff",
+        :id => 'foo', :repository_id => 'foo', :rev => '2457', :path => path
+    end
   end
 
   def test_repositories_non_revisions_path_with_repository_id
-    should_route 'GET /projects/foo/repository/svn/changes' => 'repositories#changes', :id => 'foo', :repository_id => 'svn'
+    should_route 'GET /projects/foo/repository/svn/changes' => 'repositories#changes', :id => 'foo', :repository_id => 'svn', :format => 'html'
 
-    %w(changes diff browse entry raw annotate).each do |action|
+    %w(changes browse entry raw annotate).each do |action|
       @paths.each do |path|
         should_route "GET /projects/foo/repository/svn/#{action}/#{path}" => "repositories##{action}",
-          :id => 'foo', :repository_id => 'svn', :path => path
+          :id => 'foo', :repository_id => 'svn', :path => path, :format => 'html'
       end
     end
+    @paths.each do |path|
+      should_route "GET /projects/foo/repository/svn/diff/#{path}" => "repositories#diff",
+        :id => 'foo', :repository_id => 'svn', :path => path
+    end
   end
 
   def test_repositories_related_issues_with_repository_id