Re: [PATCH mptcp-next 1/2] selftests: mptcp: run fail_test in main shell during join test

Hi Gang,

On 24/07/2026 08:52, Gang Yan wrote:
> From: Gang Yan <[email protected]>
> 
> check_transfer() compares the input and output files byte-by-byte using
> `cmp -l "$in" "$out" | while read ...`. Because the while-loop body runs
> in a subshell (the script sets neither lastpipe nor pipefail), the
> fail_test call inside it -- which sets the global ret/last_test_failed --
> and the `return 1` both act on the subshell, not on check_transfer().
> check_transfer() thus always falls through to `return 0`, and any data
> corruption affecting only the payload (leaving the subflow/PM counters
> untouched) is silently reported as PASS.

Good catch!

This looks like a fix that should be backported. Do you have a Fixes tag
to add here?

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.