Make throws in query error callback not break client

If you receive an error while running a query and in user's callback
they throw an exception it can disrupt the internal query queue
and prevent a client from ever cleaning up properly

Author: brianc

lib/client.js

@@ -173,8 +173,9 @@ Client.prototype.connect = function(callback) {
       if(self.activeQuery.isPreparedStatement) {
         con.sync();
       }
-      self.activeQuery.handleError(error);
+      var activeQuery = self.activeQuery;
       self.activeQuery = null;
+      activeQuery.handleError(error);
     }
   });
 

lib/native/query.js

@@ -58,8 +58,10 @@ NativeQuery.prototype.handleError = function(error) {
     this._canceledDueToError = false;
   }
   if(this.callback) {
-    this.callback(error);
+    var cb = this.callback;
+    //remove callback to prevent double call on readyForQuery
     this.callback = null;
+    cb(error);
   } else {
     this.emit('error', error);
   }

test/integration/client/query-callback-error-tests.js

@@ -1,22 +1,34 @@
 var helper = require(__dirname + '/test-helper');
 var util = require('util');
 
-test('error during query execution', function() {
-  var client = new Client(helper.args);
-  process.removeAllListeners('uncaughtException');
-  assert.emits(process, 'uncaughtException', function() {
-    assert.equal(client.activeQuery, null, 'should remove active query even if error happens in callback');
-    client.query('SELECT * FROM blah', assert.success(function(result) {
-      assert.equal(result.rows.length, 1);
-      client.end();
-    }));
-  });
-  client.connect(assert.success(function() {
-    client.query('CREATE TEMP TABLE "blah"(data text)', assert.success(function() {
-      var q = client.query('INSERT INTO blah(data) VALUES($1)', ['yo'], assert.success(function() {
-        assert.emits(client, 'drain');
-        throw new Error('WHOOOAAAHH!!');
+var withQuery = function(text, resultLength, cb) {
+  test('error during query execution', function() {
+    var client = new Client(helper.args);
+    process.removeAllListeners('uncaughtException');
+    assert.emits(process, 'uncaughtException', function() {
+      console.log('got uncaught exception')
+      assert.equal(client.activeQuery, null, 'should remove active query even if error happens in callback');
+      client.query('SELECT * FROM blah', assert.success(function(result) {
+        assert.equal(result.rows.length, resultLength);
+        client.end();
+        cb();
+      }));
+    });
+    client.connect(assert.success(function() {
+      client.query('CREATE TEMP TABLE "blah"(data text)', assert.success(function() {
+        var q = client.query(text, ['yo'], assert.calls(function() {
+          assert.emits(client, 'drain');
+          throw new Error('WHOOOAAAHH!!');
+        }));
       }));
     }));
-  }));
+  });
+}
+
+//test with good query so our callback is called
+//as a successful callback
+withQuery('INSERT INTO blah(data) VALUES($1)', 1, function() {
+  //test with an error query so our callback is called with an error
+  withQuery('INSERT INTO asldkfjlaskfj eoooeoriiri', 0, function() {
+  });
 });