support for 'emptyQuery' command

lib/connection.js

@@ -198,7 +198,8 @@ var messageNames = {
   1: 'parseComplete',
   2: 'bindComplete',
   A: 'notification',
-  n: 'noData'
+  n: 'noData',
+  I: 'emptyQuery'
 };
 
 p.parseMessage =  function() {
@@ -334,15 +335,18 @@ p.parseE = function(msg) {
 //same thing, different name
 p.parseN = p.parseE;
 
+//some messages are only a header portion and
+//require no more parsing
+var noParse = function(msg) { return msg; };
+
 //parses parseComplete
-p.parse1 = function(msg) {
-  return msg;
-};
+p.parse1 = noParse;
 
 //parses bindComplete
-p.parse2 = function(msg) {
-  return msg;
-};
+p.parse2 = noParse;
+
+//parse emptyQuery
+p.parseI = noParse;
 
 p.parseA = function(msg) {
   msg.processId = this.parseInt32();

test/integration/client/empty-query-tests.js

@@ -0,0 +1,8 @@
+var helper = require(__dirname+'/test-helper');
+var client = helper.client();
+
+test("empty query message handling", function() {
+  client.query("");
+  assert.raises(client.connection, 'emptyQuery');
+  client.on('drain', client.end.bind(client));
+});

test/test-buffers.js

@@ -113,4 +113,8 @@ buffers.notification = function(id, channel, payload) {
     .join(true, 'A')
 };
 
+buffers.emptyQuery = function() {
+  return new BufferList().join(true, 'I');
+};
+
 module.exports = buffers;