big_pipe.js' checkMutation() does not check if node exists before using it

Trivial hardening, yes please! 👍

Thanks!

This bug was introduced in 🐛 Large placeholders are not processed RTBC .

Can somebody convert this to an MR? 🙏😊

MR opened and patch ported there

Committed/pushed to 11.x and cherry-picked to 10.2.x, thanks!

I'm pretty sure this is the wrong fix.

We hit this error in 📌 Use selenium/standalone-chrome instead of our chromedriver image Needs work . It occurs from the second call to checkMutation in this code.

  function checkMutationAndProcess(node) {
    if (checkMutation(node)) {
      processReplacement(node);
    }
    // Checks if parent node of target node has not been processed, which can
    // occur if the script node was first observed with empty content and then
    // the child text node was added in full later.
    // @see `@ingroup large_chunk` for more information.
    else if (checkMutation(node.parentNode)) {
      processReplacement(node.parentNode);
    }
  }

There's no way that node can be a null but there is a way for node.parentNode to be NULL. In that issue we changed the code to:

    // occur if the script node was first observed with empty content and then
    // the child text node was added in full later.
    // @see `@ingroup large_chunk` for more information.
    // If an element is added and then immediately (faster than the next
    // setImmediate is triggered) removed to a watched element of a
    // MutationObserver, the observer will notice and add a mutation for both
    // the addedNode and the removedNode - but the referenced element will not
    // have a parent node.
    else if (node.parentNode !== null && checkMutation(node.parentNode)) {
      processReplacement(node.parentNode);
    }
  }

Yes the code changed here will result in fixing the problem but I think the comment and code flow are better with the changes in 📌 Use selenium/standalone-chrome instead of our chromedriver image Needs work .

Reverted, let's extract the fix from that issue to here.

Implemented the suggestion if I understood it correctly

Looks great and from the 📌 Use selenium/standalone-chrome instead of our chromedriver image Needs work issue we know it fixes the problem.

Committed and pushed da7f4e6327 to 11.x and 885932a213 to 10.2.x. Thanks!

longwave → closed merge request !6644

Marked 🐛 Cannot read properties of null (reading 'nodeType') on node.page.body RTBC as a duplicate of this.

Automatically closed - issue fixed for 2 weeks with no activity.