Fix redirects when using non-standard ports.

Commit 507972e introduced a change to the redirect method in order to
be compliant with RFC 2616's requirement that the Location header use an
"absoluteURI". However, the change relied on an undefined "port"
variable. This commit fixes that omission by using the port from the
request.

The formatting of the redirect method has also been adjusted to wrap at
approx. 78-80 characters and use "&&" and "||", like the rest of Sinatra.

Specs included.

lib/sinatra/base.rb

@@ -97,13 +97,18 @@ def block.each ; yield call ; end
     # Halt processing and redirect to the URI provided.
     def redirect(uri, *args)
       if not uri =~ /^https?:\/\//
-        # According to RFC 2616 section 14.30, “the field value consists of a single absolute URI”
-        abs_uri = request.scheme + "://"
-        abs_uri << request.host
-        abs_uri << ":#{port}" if request.scheme == "https" and request.port != 443 or request.scheme == "http" and request.port != 80
-        abs_uri << uri
-        uri = abs_uri
+        # According to RFC 2616 section 14.30, "the field value consists of a
+        # single absolute URI"
+        abs_uri = "#{request.scheme}://#{request.host}"
+
+        if request.scheme == 'https' && request.port != 443 ||
+              request.scheme == 'http' && request.port != 80
+          abs_uri << ":#{request.port}"
+        end
+
+        uri = (abs_uri << uri)
       end
+
       status 302
       response['Location'] = uri
       halt(*args)

test/helpers_test.rb

@@ -87,6 +87,30 @@ def test_default
       assert_equal 302, response.status
       assert_equal 'http://example.org/foo', response['Location']
     end
+
+    it 'redirects using a non-standard HTTP port' do
+      mock_app {
+        get '/' do
+          redirect '/foo'
+        end
+      }
+
+      request = Rack::MockRequest.new(@app)
+      response = request.get('/', 'SERVER_PORT' => '81')
+      assert_equal 'http://example.org:81/foo', response['Location']
+    end
+
+    it 'redirects using a non-standard HTTPS port' do
+      mock_app {
+        get '/' do
+          redirect '/foo'
+        end
+      }
+
+      request = Rack::MockRequest.new(@app)
+      response = request.get('/', 'SERVER_PORT' => '444')
+      assert_equal 'http://example.org:444/foo', response['Location']
+    end
   end
 
   describe 'error' do