CodeRabbit security finding on the merged sed work (CWE-693, verified live
on main via #3495): GNU sed labels for b, t, T and : end at ';' or newline —
verified against GNU sed 4.9 ('bar;e cmd' parses label 'a' and still runs
cmd; '}' is not a label terminator). Reading those operands to end of line
let 'sed :a;e git commit --no-verify' pass the hook while sed executed the
e command.
Labels are now read up to ';' or newline and command parsing resumes after
them. Text, filename and quit operands (a, c, i, r, w, q, Q) keep the
end-of-line reading: nothing after them on the line executes.
5 regression tests pin the three bypass paths and the benign boundary
(a bare label and a bare branch stay data). Suite: 817/817.