It seems not all caller of RecentChanges::newFromRow are using a row from database, so the logid is missing.

When than a tag is added, for example from AbuseFilter, it could be possible to get the undefined index.
It seems okay to just assume the default of 0 for the logid here.

https://phabricator.wikimedia.org/diffusion/EFLW/browse/master/includes/Data/Listener/RecentChangesListener.php;e910a88562f180831496ea4593479654ae95cec3$84

		if ( count( $this->tags ) ) {
			ChangeTags::addTags( $this->tags, $this->mAttribs['rc_id'],
				$this->mAttribs['rc_this_oldid'], $this->mAttribs['rc_logid'], null, $this );
		}