On Mon, 28 Nov 2016 11:32:38 GMT, hv wrote: > This is a bug report for perl from hv@crypt.org, > generated with the help of perlbug 1.40 running under perl 5.25.7. > > > ----------------------------------------------------------------- > [Please describe your issue here] > > In [perl #124368], Brian reports a second unrelated AFL-generated case > that happens to hit the same assertion in Perl_sv_2pv_flags(); in > short: > > % perl -e 'chop(@x =~ tr/1/1/)' > perl: sv.c:2941: Perl_sv_2pv_flags: Assertion `((svtype)((sv)- > >sv_flags & 0xff)) != SVt_PVAV && ((svtype)((sv)->sv_flags & 0xff)) != > SVt_PVHV && ((svtype)((sv)->sv_flags & 0xff)) != SVt_PVFM' failed. > Aborted (core dumped) > % > > Without -DDEBUGGING: > > % ./miniperl -wle '@x=(1..11); print scalar @x; print @x =~ tr/1/1/; > print chop(@x =~ tr/1/1/)' > Applying transliteration (tr///) to @x will act on scalar(@x) at -e > line 1. > Applying transliteration (tr///) to @x will act on scalar(@x) at -e > line 1. > 11 > 2 > Use of uninitialized value in transliteration (tr///) at -e line 1. > 0 > % > > The same works fine on a string, apparently happy to chop the temp > scalar: > > % ./miniperl -wle '$s="11"; print $s; print $s =~ tr/1/1/; print > chop($s =~ tr/1/1/)' > 11 > 2 > 2 > % > > .. but I note that if you throw a scalar() in there (which I'd have > expected to have no effect), both cases complain (and in rather dodgy > style): > > % ./miniperl -wle '@x=(1..11); chop(scalar(@x) =~ tr/1/1/)' > Can't modify scalar in chop at -e line 1, near "tr/1/1/) > " > Execution of -e aborted due to compilation errors. > % ./miniperl -wle '$s="11"; chop(scalar($s) =~ tr/1/1/)' > Can't modify scalar in chop at -e line 1, near "tr/1/1/) > " > Execution of -e aborted due to compilation errors. > % > > I'm not sure now what correct behaviour would be here, or how to make > it so. > In 'perldoc -f tr', I see no documentation of anything like: ##### @x =~ tr/1/1/ ##### So if that is essentially undefined behavior, then, ##### chop(@x =~ tr/1/1/) ##### would be undefined as well. -- James E Keenan (jkeenan@cpan.org) --- via perlbug: queue: perl5 status: new https://rt.perl.org/Ticket/Display.html?id=130198Thread Previous