AFAICT from https://drafts.csswg.org/css-text-3/#white-space-processing, a lone CR (U+000D) character should be treated just like a lone LF (U+000A) or a CRLF pair: it is a segment break, which will be transformed to a preserved line feed, removed, or transformed to a space (U+0020), depending on the value of white-space and possibly the context of the segment break.

However, none of the browsers I have tested so far (Firefox, Chrome, Safari, Edge) appear to behave this way; rather, they all discard the lone CR.

Testcase: https://people-mozilla.org/~jkew/tests/cr.html

Am I misunderstanding something here, should the spec be changed to better match actual behavior, or do we expect all the browsers to change to match the spec?