[daniexit]

A payload with no ANSI escape, no LF, and multiple bare CRs is a classic-Mac text document, not a progress redraw. It was classified as terminal, and collapseCarriageReturns then kept only the last line. Require an ANSI escape or at least one LF for the bare-CR heuristic.

Refs #1294

[JuliusBrussee]

Thanks @daniexit, verified: TestDetectTerminal/cr-only_3+_lines_classic_mac_not_terminal fails on main and passes here. Adopted into #1309 with your authorship. One follow-up test commit there: the pipeline test now checks that every CR-terminated line survives, not only the content type. Your empty ci: re-run perf gate commit was left out. Landed in #1309; closing.

The same document with one trailing \n still collapses, because it has exactly the shape of a progress-bar redraw. That needs a terminal-compressor change (option 3 in #1294), so #1294 stays open.