fix to allow executing queries within the callback function of another query.

there was a timing issue with emiting the drain event

lib/client.js

@@ -88,7 +88,12 @@ p.pulseQueryQueue = function() {
       this.activeQuery = query;
       query.submit(this.connection);
     } else {
-      this.emit('drain');
+      var self = this;
+      process.nextTick(function() {
+        if(this.queryQueue.length <= 0) {
+          this.emit('drain');
+        }
+      }.bind(this))
     }
   }
 };

test/integration/client/api-tests.js

@@ -4,7 +4,7 @@ var pg = require(__dirname + '/../../../lib');
 var connected = false
 var simpleCalled = false
 var preparedCalled = false
-
+var nestedCalled = false
 pg.connect(helper.args, function(err, client) {
   connected = true
   assert.equal(err, null, "Failed to connect");
@@ -38,10 +38,19 @@ pg.connect(helper.args, function(err, client) {
       assert.equal(result.rows.pop().name, 'the beach boys');
     })
   })
+
+  test('executing nested queries', function() {
+    client.query('select * FROM band', function(err, result) {
+      client.query('select * FROM band', function(err, result2) {
+        nestedCalled = true
+      })
+    })
+  })
 })
 
 process.on('exit', function() {
   assert.ok(connected, 'never connected');
+  assert.ok(nestedCalled, 'never called nested query')
   assert.ok(simpleCalled, 'query result callback was never called');
   assert.ok(preparedCalled, 'prepared callback was never called');
 })

test/unit/client/query-queue-tests.js

@@ -43,7 +43,9 @@ test("when all queries are sent", function() {
 test("after last query finishes", function() {
   con.emit('readyForQuery');
   test("emits drain", function() {
-    assert.ok(raisedDrain);
+    process.nextTick(function() {
+      assert.ok(raisedDrain);
+    })
   });
 });