From @muir

Created by @muir

I've found a paticular use of splice fails when applied to a tied
array.

Enclosed is a test that illustrates the problem.

In the code below,

  splice(@​$x, 2, 2, @​$x[3, 2]);

behaves differently from
 
  splice(@​$x, 2, 2, $x->[3], $x->[2]);

------------ cut here -----------
print "1..1\n";

my $x = [ 'a', 'b', 'c', 'd', 'e' ];

tie @​$x, 'OverArray', $x;

#print "3,2 = ".join(' ', @​$x[3, 2])."\n";

splice(@​$x, 2, 2, @​$x[3, 2]);
#splice(@​$x, 2, 2, $x->[3], $x->[2]);

#print "x = @​$x\n";

print ($x->[3] eq 'c' ? "ok 1\n" : "not ok 1\n");

package OverArray;

sub UNTIE
{
}

sub DESTROY
{
}

sub TIEARRAY
{
  my $pkg = shift;
  my $orig = shift;
  my $self = bless [ [ @​$orig ], $orig ], $pkg;
  return $self;
}

sub FETCH
{
  my $self = shift;
  my ($fake, $real) = @​$self;
  my $index = shift;
  return $fake->[$index];
}

sub STORE
{
  my $self = shift;
  my ($fake, $real) = @​$self;
  my ($index, $value) = @​_;
  $fake->[$index] = $value;
}

sub FETCHSIZE
{
  my $self = shift;
  my ($fake, $real) = @​$self;
  return scalar(@​$fake);
}

sub STORESIZE
{
  my $self = shift;
  my ($fake, $real) = @​$self;
  my $count = shift;
  $self->SPLICE($count - scalar(@​$fake))
  if $count < @​$fake;
  $#$fake = $count-1;
}

sub EXTEND
{
  my $self = shift;
  my ($fake, $real) = @​$self;
  my $count = shift;
  $#$fake = $count-1 if $count > @​$fake;
}

sub EXISTS
{
  my $self = shift;
  my ($fake, $real) = @​$self;
  my $index = shift;
  return exists($fake->[$index]);
}

sub DELETE
{
  my $self = shift;
  my ($fake, $real) = @​$self;
  delete $fake->[$index];
}

sub CLEAR
{
  my $self = shift;
  my ($fake, $real) = @​$self;
  $fake->STORESIZE(0);
}

sub PUSH
{
  my $self = shift;
  my ($fake, $real) = @​$self;
  push(@​$fake, @​_);
}

sub POP
{
  my $self = shift;
  return $self->SPLICE(-1,1);
}

sub SHIFT
{
  my $self = shift;
  return $self->SPLICE(0,1);
}

sub UNSHIFT
{
  my $self = shift;
  return $self->SPLICE(0,0,@​_);
}

sub SPLICE
{
  my $self = shift;
  my ($fake, $real) = @​$self;
  my $offset = shift || 0;
  my $length = shift;
  $offset += @​$fake if $offset < 0;
  $length = $#$fake - $offset
  unless defined $length;
  my (@​rv) = splice(@​$fake, $offset, $length, @​_);
  return @​rv;
}
------------ cut here -----------

Flags:
    category=core
    severity=medium

Site configuration information for perl v5.8.0:

Configured by muir at Wed Dec 18 00:21:13 PST 2002.

Summary of my perl5 (revision 5.0 version 8 subversion 0) configuration:
  Platform:
    osname=freebsd, osvers=4.7-release, archname=i386-freebsd
    uname='freebsd charm.idiom.com 4.7-release freebsd 4.7-release #4: thu oct 10 22:04:24 pdt 2002 muir@charm.idiom.com:charmbuildobjcharmbuildsrcsyscharm i386 '
    config_args='-sde -Dprefix=/usr/local -Darchlib=/usr/local/lib/perl5/5.8.0/mach -Dprivlib=/usr/local/lib/perl5/5.8.0 -Dman3dir=/usr/local/lib/perl5/5.8.0/man/man3 -Dsitearch=/usr/local/lib/perl5/site_perl/5.8.0/mach -Dsitelib=/usr/local/lib/perl5/site_perl/5.8.0 -Ui_malloc -Ui_iconv -Uinstallusrbinperl -Dccflags=-DAPPLLIB_EXP="/usr/local/lib/perl5/5.8.0/BSDPAN" -Ui_gdbm -Dusemymalloc=n'
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=undef use5005threads=undef useithreads=undef usemultiplicity=undef
    useperlio=define d_sfio=undef uselargefiles=define usesocks=undef
    use64bitint=undef use64bitall=undef uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-DAPPLLIB_EXP="/usr/local/lib/perl5/5.8.0/BSDPAN" -DHAS_FPSETMASK -DHAS_FLOATINGPOINT_H -fno-strict-aliasing -I/usr/local/include',
    optimize='-O -pipe -m486 -mcpu=i686 -march=pentiumpro ',
    cppflags='-DAPPLLIB_EXP="/usr/local/lib/perl5/5.8.0/BSDPAN" -DHAS_FPSETMASK -DHAS_FLOATINGPOINT_H -fno-strict-aliasing -I/usr/local/include'
    ccversion='', gccversion='2.95.4 20020320 [FreeBSD]', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
    ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
    alignbytes=4, prototype=define
  Linker and Libraries:
    ld='cc', ldflags ='-Wl,-E  -L/usr/local/lib'
    libpth=/usr/lib /usr/local/lib
    libs=-lgdbm -lm -lc -lcrypt -lutil
    perllibs=-lm -lc -lcrypt -lutil
    libc=, so=so, useshrplib=false, libperl=libperl.a
    gnulibc_version=''
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags=' '
    cccdlflags='-DPIC -fPIC', lddlflags='-shared  -L/usr/local/lib'

Locally applied patches:
    


@INC for perl v5.8.0:
    /usr/local/lib/perl5/site_perl/5.8.0/mach
    /usr/local/lib/perl5/site_perl/5.8.0
    /usr/local/lib/perl5/site_perl/5.6.1
    /usr/local/lib/perl5/site_perl/5.005
    /usr/local/lib/perl5/site_perl
    /usr/local/lib/perl5/5.8.0/BSDPAN
    /usr/local/lib/perl5/5.8.0/mach
    /usr/local/lib/perl5/5.8.0
    .


Environment for perl v5.8.0:
    HOME=/home/muir
    LANG (unset)
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=.:/home/muir/bin/charm:/home/muir/bin:/home/muir/bin/share:/bin:/usr/bin:/sbin:/usr/sbin:/usr/local/shbin:/usr/local/sbin:/usr/local/bin:/usr/local/ptybin:/usr/X11R6/bin:/usr/bin/X11:/usr/local/tex/bin:/usr/ucb:/usr/bin:/bin:/etc:/usr/etc:/usr/games:/lib:/usr/lib:/usr/local/java/bin:/usr/lib/uucp:/usr/openwin/bin:/usr/openwin/bin/xview:/usr/openwin/demo:/usr/adm:/home/muir/tmp
    PERL_BADLANG (unset)
    SHELL=/usr/local/bin/tcsh

From @ap

* muir@​charm.idiom.com (via RT) <perlbug-followup@​perl.org> [2003-06-04 21​:02]​:

I've found a paticular use of splice fails when applied to a
tied array.

Enclosed is a test that illustrates the problem.

I clearly remember there have been problems with slices read from
tied arrays before. If you instrument the code a bit you'll find
that the version which attempts to use a slice deref FETCHes them
twice (one extra time after splice() is called). This might be
going awry depending on the order of operations.

--- t.pl.orig   2003-06-05 16:50:39.000000000 +0200
+++ t.pl        2003-06-05 16:51:39.000000000 +0200
@@ -33,6 +33,7 @@
 
 sub FETCH
 {
+       warn "FETCH @_\n";
        my $self = shift;
        my ($fake, $real) = @$self;
        my $index = shift;
@@ -122,6 +123,7 @@
 
 sub SPLICE
 {
+       warn "SPLICE @_\n";
        my $self = shift;
        my ($fake, $real) = @$self;
        my $offset = shift || 0;
-----------------------------------------------------------------

-- 

Regards,
Aristotle

From p5p@spam.wizbit.be

On Wed Jun 04 12​:29​:23 2003, muir@​charm.idiom.com wrote​:

This is a bug report for perl from muir@​charm.idiom.com,
generated with the help of perlbug 1.34 running under perl v5.8.0.

-----------------------------------------------------------------
[Please enter your report here]

I've found a paticular use of splice fails when applied to a tied
array.

Enclosed is a test that illustrates the problem.

In the code below,

splice\(@​$x\, 2\, 2\, @​$x\[3\, 2\]\);

behaves differently from

splice\(@​$x\, 2\, 2\, $x\->\[3\]\, $x\->\[2\]\);

This was fixed in perl-5.8.6

perl-5.8.5 /tmp/rt-22570.pl
1..1
not ok 1

perl-5.8.6 /tmp/rt-22570.pl
1..1
ok 1

p5p@spam.wizbit.be - Status changed from 'open' to 'resolved'