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Using "my" in "until" statement modifier resetting lexicals from outer scope #17103

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p5pRT opened this issue Jul 23, 2019 · 3 comments
Open

Using "my" in "until" statement modifier resetting lexicals from outer scope #17103

p5pRT opened this issue Jul 23, 2019 · 3 comments
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type-core

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@p5pRT
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p5pRT commented Jul 23, 2019

Migrated from rt.perl.org#134303 (status was 'open')

Searchable as RT134303$
@p5pRT
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p5pRT commented Jul 23, 2019

From choroba@matfyz.cz

Created by @choroba

As stated in the Subject​: using "my" in the "until" statement modifier resets
the lexical of the same name from outer scope.

See also https://www.perlmonks.org/?node_id=11103184 and especially
the reply https://www.perlmonks.org/?node_id=11103204 for more
details.

  #!/usr/bin/perl
  use warnings;
  use strict;

  warn $];

  our $our = 1;
  warn 'never' until $our = 6;
  warn "<< $our >>"; # 6

  my $mine = 1;
  warn 'never' until $mine = 6;
  warn "<< $mine >>"; # 6

  our $nil = 1;
  warn 'never' until my $nil = 6; # my !
  warn "<< $nil >>"; # undef

  my $null = 1;
  warn 'never' until my $null = 6; # my !
  warn "<< $null >>"; # undef

When using "if" instead of "until", the output is always "6".

Thanks to LanX who is normally to busy/lazy to report perlbugs

Ch.

Perl Info 

Flags:
     category=core
     severity=medium

Site configuration information for perl 5.31.1:

Configured by choroba at Tue Jun 18 09:46:42 CEST 2019.

Summary of my perl5 (revision 5 version 31 subversion 1) configuration:
   Commit id: fa068f6da2218ae85bae1e26ee7591c15276555f
   Platform:
     osname=linux
     osvers=4.4.179-99-default
     archname=x86_64-linux-thread-multi
     uname='linux lenonovo 4.4.179-99-default #1 smp tue may 14 18:07:16 utc 2019 (c775d39) x86_64 x86_64 x86_64 gnulinux '
     config_args='-rdes -Dusethreads -Dprefix=~/blead -Dusedevel'
     hint=recommended
     useposix=true
     d_sigaction=define
     useithreads=define
     usemultiplicity=define
     use64bitint=define
     use64bitall=define
     uselongdouble=undef
     usemymalloc=n
     default_inc_excludes_dot=define
     bincompat5005=undef
   Compiler:
     cc='cc'
     ccflags ='-D_REENTRANT -D_GNU_SOURCE -fwrapv -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_FORTIFY_SOURCE=2'
     optimize='-O2'
     cppflags='-D_REENTRANT -D_GNU_SOURCE -fwrapv -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include'
     ccversion=''
     gccversion='4.8.5'
     gccosandvers=''
     intsize=4
     longsize=8
     ptrsize=8
     doublesize=8
     byteorder=12345678
     doublekind=3
     d_longlong=define
     longlongsize=8
     d_longdbl=define
     longdblsize=16
     longdblkind=3
     ivtype='long'
     ivsize=8
     nvtype='double'
     nvsize=8
     Off_t='off_t'
     lseeksize=8
     alignbytes=8
     prototype=define
   Linker and Libraries:
     ld='cc'
     ldflags =' -fstack-protector -L/usr/local/lib'
     libpth=/usr/local/lib /usr/lib64/gcc/x86_64-suse-linux/4.8/include-fixed /usr/lib64/gcc/x86_64-suse-linux/4.8/../../../../x86_64-suse-linux/lib /usr/lib /lib/../lib64 /usr/lib/../lib64 /lib /lib64 /usr/lib64 /usr/local/lib64
     libs=-lpthread -lnsl -lgdbm -ldl -lm -lcrypt -lutil -lc -lgdbm_compat
     perllibs=-lpthread -lnsl -ldl -lm -lcrypt -lutil -lc
     libc=libc-2.22.so
     so=so
     useshrplib=false
     libperl=libperl.a
     gnulibc_version='2.22'
   Dynamic Linking:
     dlsrc=dl_dlopen.xs
     dlext=so
     d_dlsymun=undef
     ccdlflags='-Wl,-E'
     cccdlflags='-fPIC'
     lddlflags='-shared -O2 -L/usr/local/lib -fstack-protector'



@INC for perl 5.31.1:
     /home/choroba/blead/lib/perl5/site_perl/5.31.1/x86_64-linux-thread-multi
     /home/choroba/blead/lib/perl5/site_perl/5.31.1
     /home/choroba/blead/lib/perl5/5.31.1/x86_64-linux-thread-multi
     /home/choroba/blead/lib/perl5/5.31.1


Environment for perl 5.31.1:
     HOME=/home/choroba
     LANG=en_US.utf8
     LANGUAGE (unset)
     LC_CTYPE=en_US.UTF-8
     LD_LIBRARY_PATH (unset)
     LOGDIR (unset)
     PATH=/home/choroba/bin:/usr/local/bin:/usr/bin:/bin:/usr/bin/X11:/home/jan.stepanek/perl5/bin:/home/jan.stepanek/opensource/worktime/bin:.
     PERL_BADLANG (unset)
     SHELL=/bin/bash

@p5pRT
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p5pRT commented Jul 31, 2019

From @tonycoz

On Tue, 23 Jul 2019 08​:00​:01 -0700, choroba@​matfyz.cz wrote​:

As stated in the Subject​: using "my" in the "until" statement modifier
resets
the lexical of the same name from outer scope.

See also https://www.perlmonks.org/?node_id=11103184 and especially
the reply https://www.perlmonks.org/?node_id=11103204 for more
details.

#!/usr/bin/perl
use warnings;
use strict;

warn $];

our $our = 1;
warn 'never' until $our = 6;
warn "<< $our >>"; # 6

my $mine = 1;
warn 'never' until $mine = 6;
warn "<< $mine >>"; # 6

our $nil = 1;
warn 'never' until my $nil = 6; # my !
warn "<< $nil >>"; # undef

my $null = 1;
warn 'never' until my $null = 6; # my !
warn "<< $null >>"; # undef

When using "if" instead of "until", the output is always "6".

Thanks to LanX who is normally to busy/lazy to report perlbugs

newLOOPOP() calls op_scope() to wrap the statement in an enter/leave pair, and since padsv does a save_clearsv() for the my variable, it's cleared by the leave.

Tony

@p5pRT
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p5pRT commented Jul 31, 2019

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

@xenu xenu removed the affects-5.31 label Nov 19, 2021
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