From @masak

<Guest56815> p6​: spurt('/tmp/ABCD.txt', "A\nB\nC\nD"); for
'/tmp/ABCD.txt'.IO.lines() -> $x, $y { say "$x, then $y"; }
<camelia> rakudo-moar 0cca60​: OUTPUT«spurt is disallowed in restricted
setting [...]
<Guest56815> Okay. When running that code, I get "A, then B C, then D
Too few positionals passed; expected 2 arguments but got 0 [...]
<masak> Guest56815​: interesting. sounds like a bug. if there are 0
arguments then the loop should be over.
* masak tries to reproduce locally
<masak> yep, reproduced.
* masak submits rakudobug
<Guest56815> Thanks!
<masak> golfed​:
<masak> m​: for "A\nB\nC\nD".lines() -> $x, $y { say "$x, then $y" }
<camelia> rakudo-moar 0cca60​: OUTPUT«A, then B␤C, then D␤Too few
positionals passed; expected 2 arguments but got 0 [...]
<masak> no need for &spurt :)
<jnthn> m​: for |(1, 2), |(3, 4), |() -> $x, $y { say "$x, then $y" }
<camelia> rakudo-moar 0cca60​: OUTPUT«1, then 2␤3, then 4␤»
<jnthn> Hm, not that... :)
<masak> m​: for "A\nB\nC\nD".lines() -> $x { say $x }
<camelia> rakudo-moar 0cca60​: OUTPUT«A␤B␤C␤D␤»
<masak> m​: for [1,2,3,4] -> $x, $y { say "$x, then $y" }
<camelia> rakudo-moar 0cca60​: OUTPUT«1, then 2␤3, then 4␤»
<masak> ok, so something fishy with lines()
<jnthn> m​: my \i = "A\nB\nC\nD".lines.iterator; my @​x; (say
i.push-exactly(@​x, 2)) xx 3
<camelia> rakudo-moar 0cca60​: OUTPUT«2␤2␤0␤»
<jnthn> m​: my \i = <A B C D>.iterator; my @​x; (say i.push-exactly(@​x, 2)) xx 3
<camelia> rakudo-moar 0cca60​: OUTPUT«2␤2␤␤»
<jnthn> That's the discrepancy. The push-many in the lines iterator is
returning 0 when it should return IterationEnd
* masak adds that to the ticket

From @molecules

Attached are two examples that recreate the problem, one using "string.IO.lines()" and the other using "string.lines()".

(This is perl6 version 2015.09-234-gbd22d7e built on MoarVM version 2015.09-39-g1434283)

From @molecules

filename_IO_lines_error.p6

From @molecules

string_lines_error.p6

The RT System itself - Status changed from 'new' to 'open'

From @molecules

This earlier Perl6 version did NOT have this problem​:

perl6 version 2015.05-55-gd84bbbc built on MoarVM version 2015.05

Thanks!

From @AlexDaniel

This bug no longer exists in the latest versions of rakudo.

There is also a PR with a test​: Raku/roast#83

In other words, this ticket may be closed once the test is accepted.

@smls - Status changed from 'open' to 'resolved'