[perl #113868] formline mis-counts characters

# New Ticket Created by  dakkar 
# Please include the string:  [perl #113868]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org:443/rt3/Ticket/Display.html?id=113868 >


This is a bug report for perl from dakkar@thenautilus.net,
generated with the help of perlbug 1.39 running under perl 5.17.2.

-----------------------------------------------------------------

This is essentially a duplicate of bug #33832.

When using formats with character strings containing characters outside of ASCII, formline cuts the string at the wrong place, resulting in weird output.

The following test shows the issue:

#!/usr/bin/env perl
use Test::More;
use strict;
use warnings;
use utf8;
use feature 'unicode_strings';

sub check_format_lines {
    my ($format,$count) = @_;
    my $output='';
    open my $fh,'>:utf8',\$output;
    my $oldfh=select $fh;
    $~=$format;
    write;
    select $oldfh;
    close $fh;
    my $lines_count = () = $output =~ m{^}mg;
    is($lines_count,$count)
        or note $output;
}

my $test;
format TEST =
{^<<<<<<}~~
$test
.

$test ='TEST[ààèèììòòùù123456789]';
check_format_lines('TEST',4);

$test ='TEST[ààèèììòòùù123456789ß]';
check_format_lines('TEST',4);

$test ='TEST[à]';
check_format_lines('TEST',1);

$test ='[à]';
check_format_lines('TEST',1);

$test ='[a]';
check_format_lines('TEST',1);

$test ='TEST[a]';
check_format_lines('TEST',1);

done_testing();

[Please do not change anything below this line]
-----------------------------------------------------------------
---
Flags:
    category=core
    severity=medium
---
Site configuration information for perl 5.17.2:

Configured by dakkar at Wed Jun 27 14:54:57 BST 2012.

Summary of my perl5 (revision 5 version 17 subversion 2) configuration:
  Snapshot of: 989843c833048f47253702c8ffd749d2315cbe3c
  Platform:
    osname=linux, osvers=3.2.12-gentoo, archname=x86_64-linux
    uname='linux exelion 3.2.12-gentoo #7 smp preempt mon may 28 14:42:47 bst 2012 x86_64 intel(r) xeon(r) cpu e5430 @ 2.66ghz genuineintel gnulinux '
    config_args='-de -Dprefix=/home/dakkar/perl5/perlbrew/perls/perl-blead -Dusedevel'
    hint=recommended, useposix=true, d_sigaction=define
    useithreads=undef, usemultiplicity=undef
    useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
    use64bitint=define, use64bitall=define, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-fno-strict-aliasing -pipe -fstack-protector -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-O2',
    cppflags='-fno-strict-aliasing -pipe -fstack-protector'
    ccversion='', gccversion='4.5.3', gccosandvers=''
    intsize=4, longsize=8, ptrsize=8, doublesize=8, byteorder=12345678
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16
    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 /lib/../lib64 /usr/lib/../lib64 /lib /usr/lib /lib64 /usr/lib64 /usr/local/lib64
    libs=-lnsl -lgdbm -ldb -ldl -lm -lcrypt -lutil -lc -lgdbm_compat
    perllibs=-lnsl -ldl -lm -lcrypt -lutil -lc
    libc=/lib/libc-2.14.1.so, so=so, useshrplib=false, libperl=libperl.a
    gnulibc_version='2.14.1'
  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'

Locally applied patches:
    

---
@INC for perl 5.17.2:
    /home/dakkar/perl5/perlbrew/perls/perl-blead/lib/site_perl/5.17.2/x86_64-linux
    /home/dakkar/perl5/perlbrew/perls/perl-blead/lib/site_perl/5.17.2
    /home/dakkar/perl5/perlbrew/perls/perl-blead/lib/5.17.2/x86_64-linux
    /home/dakkar/perl5/perlbrew/perls/perl-blead/lib/5.17.2
    .

---
Environment for perl 5.17.2:
    HOME=/home/dakkar
    LANG (unset)
    LANGUAGE (unset)
    LC_ALL=en_US.UTF-8
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/home/dakkar/perl5/perlbrew/bin:/home/dakkar/perl5/perlbrew/perls/perl-blead/bin:/home/dakkar/bin:/usr/local/bin:/usr/bin:/bin:/opt/bin:/usr/x86_64-pc-linux-gnu/gcc-bin/4.5.3
    PERLBREW_BASHRC_VERSION=0.41
    PERLBREW_HOME=/home/dakkar/.perlbrew
    PERLBREW_MANPATH=/home/dakkar/perl5/perlbrew/perls/perl-blead/man
    PERLBREW_PATH=/home/dakkar/perl5/perlbrew/bin:/home/dakkar/perl5/perlbrew/perls/perl-blead/bin
    PERLBREW_PERL=perl-blead
    PERLBREW_ROOT=/home/dakkar/perl5/perlbrew
    PERLBREW_VERSION=0.41
    PERL_BADLANG (unset)
    SHELL=/bin/bash

• [perl #113868] formline mis-counts characters by dakkar