**Do you want to request a *feature* or report a *bug*?**

bug? Maybe.

**What is the current behavior?**

Using non-delegated handler for submit event.

**What is the expected behavior?**

After IE9, at least I know, submit event bubbled up.

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**

16.2.0
if (__DEV__) {
    if (didWarnInvalidHydration) {
      return;
    }
    didWarnInvalidHydration = true;
    warningWithoutStack(
      false,
      'Did not expect server HTML to contain a <%s> in <%s>.',
      child.nodeName.toLowerCase(),
      parentNode.nodeName.toLowerCase(),
    );
  }
}
export function warnForDeletedHydratableText(
  parentNode: Element | Document,
  child: Text,
) {
  if (__DEV__) {
    if (didWarnInvalidHydration) {
      return;
    }
    didWarnInvalidHydration = true;
    warningWithoutStack(
      false,
      'Did not expect server HTML to contain the text node "%s" in <%s>.',
      child.nodeValue,
      parentNode.nodeName.toLowerCase(),
    );
  }
}