On the Wikidata Project chat I just happened to notice another comment that’s recognized as part of a reply to it; the unrecognized comment is again unsigned, but this time on the top level:

The unrecognized comment has a left-to-right mark after the time: (https://en.wikipedia.org/wiki/Left-to-right_mark)

We should probably support this. We already handle them appearing after the date (see T245784).

Thanks for the tip, it makes sense: I copied the second timestamp from the page history (only the time part, as I use Hungarian interface, so the date part would have been of no use), while I decided to retype the first one. To support already-existing such unsigned templates, it would be useful to remove all LTR/RTL marks from the text before recognizing the timestamps, but to prevent new ones, I think the page history shouldn’t contain them in the first place; incorrect positioning should be prevented at the HTML (<bdi>) / CSS (unicode-bidi) level instead.

For reference, here's a history page with the LRMs marked:

lrm = '\u200E';
treeWalker = document.createTreeWalker(
	document.body,
	NodeFilter.SHOW_TEXT,
	function ( node ) {
		if ( node.textContent.indexOf( lrm ) !== -1 ) {
			return NodeFilter.FILTER_ACCEPT;
		}
		return NodeFilter.FILTER_SKIP;
	},
	false
);
while ( node = treeWalker.nextNode() ) {
	newNode = node.splitText( node.textContent.indexOf( lrm ) );
	treeWalker.currentNode = newNode.splitText( 1 );
	wrap = document.createElement( 'span' );
	wrap.style.cssText = 'outline: 1px solid red; outline-offset: 3px;';
	newNode.parentNode.insertBefore( wrap, newNode );
	wrap.appendChild( newNode );
}

…and the same in Hungarian:

This explains how you ended up with the LRM there, it's because the time is at the end in the date format used in Hungarian. It was probably obvious to you, but very confusing to me.

In T308448#7931413, @Lucas_Werkmeister_WMDE wrote:

On the Wikidata Project chat I just happened to notice another comment that’s recognized as part of a reply to it; the unrecognized comment is again unsigned, but this time on the top level:

It might be related to “unsigned” templates after all, even if it doesn’t always happen?

This is actually a different problem – the date format for the unsigned comment is incorrect (different than in normal signatures) – "May 16, 2022‎" instead of "16 May 2022". (And there's also a stray LRM, but it should be harmless here.)

By the way, if you enable syntax highlighting, it will mark LRMs and other invisible characters:

Change 792295 had a related patch set uploaded (by Bartosz Dziewoński; author: Bartosz Dziewoński):

[mediawiki/extensions/DiscussionTools@master] Ignore LRM and RLM in more places in the timestamp

https://gerrit.wikimedia.org/r/792295

Change 792295 merged by jenkins-bot:

[mediawiki/extensions/DiscussionTools@master] Ignore LRM and RLM in more places in the timestamp

https://gerrit.wikimedia.org/r/792295