From cuer2s@gmail.com

http://stackoverflow.com/questions/36208514/perl6-why-does-substr-rw-behave-this-way

From @AlexDaniel

Not sure if this is related, but it reminds me of this​: https://rt-archive.perl.org/perl6/Ticket/Display.html?id=123602

From @zoffixznet

Still present on rakudo 89470a​:

<Zoffix> m​: my $a = '.' x 3 ~ 'x'; my $b = sprintf('%s', $a); say $a; say $b; $a.substr-rw( 0, 2 ) = ''; $b.substr-rw( 0, 2 ) = ''; say $a; say $b;
<camelia> rakudo-moar 89470a​: OUTPUT«...x␤...x␤..␤.x␤»

From @zoffixznet

A bit more investigation​:
* If the string given to `x` is more than 1 character, the bug doesn't appear
* The bug also doesn't seem to be present on JVM backend

<Zoffix> m​: my $a = '.|' x 4 ~ 'a'; $a.substr-rw(1,1) = ''; say $a
<camelia> rakudo-moar 713ad5​: OUTPUT«..|.|.|a␤»
<Zoffix> m​: my $a = '.' x 4 ~ 'a'; $a.substr-rw(1,1) = ''; say $a
<camelia> rakudo-moar 713ad5​: OUTPUT«....␤»
<Zoffix> j​: my $a = '.' x 4 ~ 'a'; $a.substr-rw(1,1) = ''; say $a
<camelia> rakudo-jvm cd19db​: OUTPUT«...a␤»

♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥
🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁

TODO-fudged tests added in Raku/roast@3f964dca6d

🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁
♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥

--
Cheers,
ZZ | https://twitter.com/zoffix

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

From @jnthn

On Wed Jul 20 19​:43​:32 2016, cpan@​zoffix.com wrote​:

A bit more investigation​:
* If the string given to `x` is more than 1 character, the bug doesn't
appear
* The bug also doesn't seem to be present on JVM backend

<Zoffix> m​: my $a = '.|' x 4 ~ 'a'; $a.substr-rw(1,1) = ''; say $a
<camelia> rakudo-moar 713ad5​: OUTPUT«..|.|.|a␤»
<Zoffix> m​: my $a = '.' x 4 ~ 'a'; $a.substr-rw(1,1) = ''; say $a
<camelia> rakudo-moar 713ad5​: OUTPUT«....␤»
<Zoffix> j​: my $a = '.' x 4 ~ 'a'; $a.substr-rw(1,1) = ''; say $a
<camelia> rakudo-jvm cd19db​: OUTPUT«...a␤»

♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥
🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁

TODO-fudged tests added in
Raku/roast@3f964dca6d

🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁🏁
♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥♥

This was effectively a dupe of RT #​123602, which I've just fixed. Untodo'd the now-passing spectest in substr-rw.t.

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