From @lizmat

[12​:37​:11] <[Tux]> https://gist.github.com/Tux/6e06f3a455a8995adda4 <= WHO BROKE IO?
[12​:37​:27] lizmat guesses jnthn :-)
[12​:37​:39] <lizmat> perhaps rakudobug it
[12​:38​:52] <lizmat> oddly enough, slurping the file shows only 1 +
[12​:39​:00] <[Tux]> This is something I have no workaround for :/
[12​:39​:25] <lizmat> this is something that is *bad* need of a fix
[12​:41​:09] <lizmat> building latest jvm, to make sure it *is* Moar related
[12​:43​:50] <lizmat> .IO.spurt("+"),.IO.open.get.perl.say for "t.csv"; # further golf
[12​:44​:36] <lizmat> fwiw, even a null byte gets copied
[12​:44​:57] <lizmat> $ 6 '.IO.spurt("\0"),.IO.open.get.perl.say for "t.csv"'
[12​:44​:57] <lizmat> "\x[0]\x[0]"
[12​:45​:36] <lizmat> feels like an off-by-one error deep in the bowels of Moar
[12​:46​:31] <lizmat> [Tux]​: will you rakudobug it or shall I ?
[12​:50​:08] <[Tux]> please do (not me)
[12​:51​:38] <lizmat> $ perl6-j -e '.IO.spurt("*"),.IO.open.get.perl.say for "t.csv"'
[12​:51​:38] <lizmat> "*"
[12​:51​:44] <lizmat> so confirmed, a Moar only bug

From @jnthn

On Sun Apr 26 03​:53​:06 2015, elizabeth wrote​:

[12​:37​:11] <[Tux]>
https://gist.github.com/Tux/6e06f3a455a8995adda4 <= WHO BROKE IO?
[12​:37​:27] lizmat guesses jnthn :-)
[12​:37​:39] <lizmat> perhaps rakudobug it
[12​:38​:52] <lizmat> oddly enough, slurping the file shows only 1 +
[12​:39​:00] <[Tux]> This is something I have no workaround for :/
[12​:39​:25] <lizmat> this is something that is *bad* need of a fix
[12​:41​:09] <lizmat> building latest jvm, to make sure it *is* Moar
related
[12​:43​:50] <lizmat> .IO.spurt("+"),.IO.open.get.perl.say for
"t.csv"; # further golf
[12​:44​:36] <lizmat> fwiw, even a null byte gets copied
[12​:44​:57] <lizmat> $ 6 '.IO.spurt("\0"),.IO.open.get.perl.say for
"t.csv"'
[12​:44​:57] <lizmat> "\x[0]\x[0]"
[12​:45​:36] <lizmat> feels like an off-by-one error deep in the
bowels of Moar
[12​:46​:31] <lizmat> [Tux]​: will you rakudobug it or shall I ?
[12​:50​:08] <[Tux]> please do (not me)
[12​:51​:38] <lizmat> $ perl6-j -e
'.IO.spurt("*"),.IO.open.get.perl.say for "t.csv"'
[12​:51​:38] <lizmat> "*"
[12​:51​:44] <lizmat> so confirmed, a Moar only bug

Indeed; it resulted from a thinko while integrating the normalization with the UTF-8 decoding (both of which need to work in a streaming fashion, since codepoints may dangle over byte-buffer read boundaries, and graphemes in turn over those codepoints). Fixed now in MoarVM; added a test in S16-io/basic-open.t.

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

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