Perl 5 has always had the ‘don't match same null twice’ comment
in pp_subst. Originally it was a parenthetical note right below
the s == m.
71be2cbc removed the parentheses. Commit
f722798be moved it further
away from s == m. Now what it refers to is far from clear.
d += clen;
}
s = RX_OFFS(rx)[0].end + orig;
- } while (CALLREGEXEC(rx, s, strend, orig, s == m,
+ } while (CALLREGEXEC(rx, s, strend, orig,
+ s == m, /* don't match same null twice */
TARG, NULL,
- /* don't match same null twice */
REXEC_NOT_FIRST|REXEC_IGNOREPOS|REXEC_FAIL_ON_UNDERFLOW));
if (s != d) {
I32 i = strend - s;