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Postings from September 2013
On Sun, Sep 15, 2013 at 3:21 PM, James E Keenan via RT <
perlbug-followup@perl.org> wrote:
> On Sun Sep 15 03:08:16 2013, glitchmr@myopera.com wrote:
>
> 1. I cannot reproduce the error you cite. I cannot generate this error:
> ""Bizarre copy of ARRAY in block exit".
>
I can, with 5.14.2 and some rewriting of the code.
I don't have a more recent version readily available, so it may well be
fixed now, but ... essentially it's the same as the OP reported, so here
goes:
2. Did you try running your program with 'use strict; use warnings;'?
> If so, you would have gotten messages that indicated problematic code.
>
I did. They went away once I declared @array and ... added some lvalue
(even read-only) to the if-branch ... perhaps 5.14.2 optimizes differently?
3. Did you try rewriting your program to name the subroutine something
> other than 'array'? That only made for a more confusing bug report.
>
> Once I started to debug this with steps 2 and 3 above, I found that I
> could get an executable (though not very useful) program by simply
> placing '()' after the subroutine call.
>
> ##########
> $ cat 119797-lvalue.pl
> my @this = (1..5);
>
> (that()) = ();
> print "@this\n";
>
> sub that :lvalue { if (@this) { } else { @this; } }
> ##########
> $ perl 119797-lvalue.pl
> 1 2 3 4 5
> ##########
>
> I don't think there is a bug here.
>
Your rewrite gets two things wrong:
First, to trigger the bug, the else-branch must be taken, so @this should
be empty or the conditional changed.
Second, your need for the '()' stems from declaring &that after using it
... ;-)
Additionally, I added a (read-only) lvalue to the if-branch, to avoid
perl 5.14.2 going down a different internal path ...
##########
use strict;
use warnings;
my @this;
sub that :lvalue { if (@this) { $& } else { @this; } }
(that) = ();
print "@this\n";
##########
perl /home/eirik/tmp/kladd.pl
Bizarre copy of ARRAY in block exit at /home/eirik/tmp/kladd.pl line 6.
##########
Eirik
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