Fix - issue #12765 / the checked attribute is not initially set on the input

Author: Wensheng Xu

packages/react-dom/src/__tests__/ReactDOMInput-test.js

@@ -739,9 +739,12 @@ describe('ReactDOMInput', () => {
     const cNode = stub.refs.c;
 
     expect(aNode.checked).toBe(true);
+    expect(aNode.getAttribute('checked')).toBe('');
     expect(bNode.checked).toBe(false);
+    expect(bNode.getAttribute('checked')).toBe(null);
     // c is in a separate form and shouldn't be affected at all here
     expect(cNode.checked).toBe(true);
+    expect(cNode.getAttribute('checked')).toBe('');
 
     bNode.checked = true;
     // This next line isn't necessary in a proper browser environment, but
@@ -750,6 +753,11 @@ describe('ReactDOMInput', () => {
     aNode.checked = false;
     expect(cNode.checked).toBe(true);
 
+    // The original 'checked' attribute should be unchanged
+    expect(aNode.getAttribute('checked')).toBe('');
+    expect(bNode.getAttribute('checked')).toBe(null);
+    expect(cNode.getAttribute('checked')).toBe('');
+
     // Now let's run the actual ReactDOMInput change event handler
     ReactTestUtils.Simulate.change(bNode);
 

packages/react-dom/src/client/ReactDOMFiberInput.js

@@ -242,7 +242,7 @@ export function postMountWrapper(
   if (name !== '') {
     node.name = '';
   }
-  node.defaultChecked = !node.defaultChecked;
+  node.defaultChecked = !node._wrapperState.initialChecked;
   node.defaultChecked = !node.defaultChecked;
   if (name !== '') {
     node.name = name;