React 15 breaks server rendering check-sum

[buzinas]

I'm developing an universal app with React, and after updating to v15.0.1, I started getting this error:

Warning: React attempted to reuse markup in a container but the checksum was invalid. This generally means that you are using server rendering and the markup generated on the server was not what the client was expecting. React injected new markup to compensate which works but you have lost many of the benefits of server rendering. Instead, figure out why the markup being generated is different on the client or server:
(client) ut class="md-input" name="txtCadmus" pat
(server) ut class="md-input" pattern="[0-9]*" nam

It seems to be some bug on V8 Object.assign reordering or something like that, but I'm not completely sure.

Tried to change a bunch of stuff (e.g: force both server and client to use a polyfill, or using Babel transform object-assign plugin), but nothing solved the problem.

Then, I uninstalled React 15.0.1 and installed 0.14.8 again, and the problem was gone.

Btw, it's pretty simple to simulate the issue:

Code

ReactDOM.render(
  <input name="my-input" className="my-class" type="number" pattern="[0-9]*" />, document.querySelector('#main')
);

console.log(document.querySelector('#main').innerHTML)

console.log(ReactDOMServer.renderToString(
  <input name="my-input" className="my-class" type="number" pattern="[0-9]*" />
));

React 15 not working

React 0.14.8 working as expected

[zdila]

I have the same issue. Some of the compared server/client elements have same attributes but in different order. React then treats them as different. Strange is that in my case ordering changes not before first page reload. Very first rendering is OK.

[gaearon]

Yes, please track this in #6451.