suspected browser workaround for broken websites

[Robert Riches]

(I searched for an answer to this but was not able to find
anything relevant.)

My wife has encountered an odd problem on a website, and I have
duplicated the symptoms and have a theory about the cause. When
I reported the problem as a bug, the response was that the site
works fine in Chrome.

The site is https://www.familysearch.org/ and the symptom is that
some pages that are supposed to show source documents have links
that go to just https://familysearch.org/... but those requests
time out with Firefox 60.3.0esr. However, if I prepend a "www."
to the FQDN, the requests go through and return the expected
documents. Someone else tried the same URLs with Firefox 63.0.1,
and the pages/documents loaded fine for him.

My theory is that Chrome and later Firefox versions work around
broken websites by prepending "www." to the URL if the first
request does not return within some short time, maybe around a
second or so.

Can anyone confirm that this workaround by browsers is being
done?

Thanks.

--
Robert Riches
spamt...@jacob21819.net
(Yes, that is one of my email addresses.)