EventLog misses some node update events

[gjwnc]

Description

Updating a node in the inspector, like hide, does not get logged in the EventLog.

Cause of the issue

In ContentRepositoryIntegrationService the Node Update event is actually received, and only the node is added to the changedNodes list:

$this->changedNodes[$node->getContextPath()] = ['node' => $node];

Later, when doctrine, sends the preFlush signal, the generateNodeEvents() is called. The loop over the changedNodes removes the node entry from $data via unset.

Thus $data is empty and the log event is not inserted because of the !empty check.

Steps to Reproduce

1. Log into the backend
2. For a document, enable or disable Hide in the inspector
3. Click the Apply button

Expected behavior

In the neos_eventsourcing_eventstore_events should be an entry that the given node was modified.
It would be nice to also know what exactly changed.

Actual behavior

No DB entry is created

Affected Versions

Neos: 3.x, 4.x, 5.x, 7.x

Notes

I would like to provide a PR, but I'm not sure about the format of $data in this case and how I can determine what exactly changed to get an old, new entry in the DB for the relevant Node model attributes. How do I know, what changed and if this should actually be logged? Are there any node updates which shouldn't be logged?

[mhsdesign]

Fyi in case this does not get fixed, we can close it as unplanned because Neos 9.0 removed the GUI event log thingy for now ^^ #4553