Don't transfer children in transferPropsTo

06cff60bc1 made it so that `this.props.children` was no longer set when
none were provided.

  var x = <div />;

This caused an issue if the code was relying on the following not
transferring children.

  return this.transferPropsTo(<div />);
  // this now transfer children

src/core/ReactPropTransferer.js

@@ -44,13 +44,17 @@ function createTransferStrategy(mergeStrategy) {
  */
 var TransferStrategies = {
   /**
-   * Never transfer the `ref` prop.
+   * Never transfer `children`.
    */
-  ref: emptyFunction,
+  children: emptyFunction,
   /**
    * Transfer the `className` prop by merging them.
    */
   className: createTransferStrategy(joinClasses),
+  /**
+   * Never transfer the `ref` prop.
+   */
+  ref: emptyFunction,
   /**
    * Transfer the `style` prop (which is an object) by merging them.
    */

src/core/__tests__/ReactCompositeComponentTransferProps-test.js

@@ -51,7 +51,7 @@ describe('ReactCompositeComponent-transferProps', function() {
     ReactTestUtils.renderIntoDocument(instance);
 
     reactComponentExpect(instance)
-      .expectRenderedChild(instance)
+      .expectRenderedChild()
         .toBeDOMComponentWithTag('input')
         .scalarPropsEqual({
           className: 'textinput',
@@ -66,7 +66,7 @@ describe('ReactCompositeComponent-transferProps', function() {
     ReactTestUtils.renderIntoDocument(instance);
 
     reactComponentExpect(instance)
-      .expectRenderedChild(instance)
+      .expectRenderedChild()
         .toBeDOMComponentWithTag('input')
         .scalarPropsEqual({placeholder: 'Type here...'});
   });
@@ -80,7 +80,7 @@ describe('ReactCompositeComponent-transferProps', function() {
     ReactTestUtils.renderIntoDocument(instance);
 
     reactComponentExpect(instance)
-      .expectRenderedChild(instance)
+      .expectRenderedChild()
         .toBeDOMComponentWithTag('input')
         .scalarPropsEqual({
           className: 'textinput hidden_elem',
@@ -91,6 +91,25 @@ describe('ReactCompositeComponent-transferProps', function() {
         });
   });
 
+  it('should not transfer children', function() {
+    var ChildrenTestComponent = React.createClass({
+      render: function() {
+        return this.transferPropsTo(<div />);
+      }
+    });
+
+    var instance =
+      <ChildrenTestComponent>
+        <span>Hello!</span>
+      </ChildrenTestComponent>;
+
+    ReactTestUtils.renderIntoDocument(instance);
+    reactComponentExpect(instance)
+      .expectRenderedChild()
+        .toBeDOMComponentWithTag('div')
+        .toBeDOMComponentWithNoChildren();
+  });
+
   it('should not transfer ref', function() {
     var RefTestComponent = React.createClass({
       render: function() {