[perl #32687] Encode::is_utf8 on tainted UTF8 string returns false

# New Ticket Created by  Mark Martinec 
# Please include the string:  [perl #32687]
# in the subject line of all future correspondence about this issue. 
# <URL: http://rt.perl.org:80/rt3/Ticket/Display.html?id=32687 >


This is a bug report for perl from Mark.Martinec@ijs.si,
generated with the help of perlbug 1.35 running under perl v5.8.5.


-----------------------------------------------------------------
The Encode::is_utf8() on an UTF-8 character string
returns false if the string is tainted.
(whereas the utf8::is_utf8 produces correct results)

INCORRECT:  ($a is tainted)
  perl -Te 'use Encode; $a="\x{263a}.$0";
            printf "(%s,%s)\n", Encode::is_utf8($a), utf8::is_utf8($a)'
  (,1)

correct:   ($a not tainted)
  perl -Te 'use Encode; $a="\x{263a}";
            printf "(%s,%s)\n", Encode::is_utf8($a), utf8::is_utf8($a)'
  (1,1)

As far as I tried, this is not specific to a platform.

-----------------------------------------------------------------
---
Flags:
    category=library
    severity=medium
---
Site configuration information for perl v5.8.5:

Configured by mark at Fri Oct  1 19:18:35 CEST 2004.

Summary of my perl5 (revision 5 version 8 subversion 5) configuration:
  Platform:
    osname=freebsd, osvers=5.3-beta4, archname=amd64-freebsd
    uname='freebsd ezri.ijs.si 5.3-beta4 freebsd 5.3-beta4 #0: sat sep 18 04:22:33 cest 2004 lesi@ezri.ijs.si:usrobjusrsrcsysezri amd64 '
    config_args='-sde -Dprefix=/usr/local -Darchlib=/usr/local/lib/perl5/5.8.5/mach -Dprivlib=/usr/local/lib/perl5/5.8.5 -Dman3dir=/usr/local/lib/perl5/5.8.5/perl/man/man3 -Dman1dir=/usr/local/man/man1 -Dsitearch=/usr/local/lib/perl5/site_perl/5.8.5/mach -Dsitelib=/usr/local/lib/perl5/site_perl/5.8.5 -Dscriptdir=/usr/local/bin -Dsiteman3dir=/usr/local/lib/perl5/5.8.5/man/man3 -Dsiteman1dir=/usr/local/man/man1 -Ui_malloc -Ui_iconv -Uinstallusrbinperl -Dcc=cc -Doptimize=-O2 -pipe  -Duseshrplib -Dccflags=-DAPPLLIB_EXP="/usr/local/lib/perl5/5.8.5/BSDPAN" -Dd_dosuid=define -Ui_gdbm -Dusethreads=n -Dusemymalloc=y -Duse64bitint'
    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=define use64bitall=define uselongdouble=undef
    usemymalloc=y, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-DAPPLLIB_EXP="/usr/local/lib/perl5/5.8.5/BSDPAN" -DHAS_FPSETMASK -DHAS_FLOATINGPOINT_H -fno-strict-aliasing -pipe -I/usr/local/include',
    optimize='-O2 -pipe ',
    cppflags='-DAPPLLIB_EXP="/usr/local/lib/perl5/5.8.5/BSDPAN" -DHAS_FPSETMASK -DHAS_FLOATINGPOINT_H -fno-strict-aliasing -pipe -I/usr/local/include'
    ccversion='', gccversion='3.4.2 [FreeBSD] 20040728', 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 ='-Wl,-E  -L/usr/local/lib'
    libpth=/usr/lib /usr/local/lib
    libs=-lm -lcrypt -lutil -lc
    perllibs=-lm -lcrypt -lutil -lc
    libc=, so=so, useshrplib=true, libperl=libperl.so
    gnulibc_version=''
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='  -Wl,-R/usr/local/lib/perl5/5.8.5/mach/CORE'
    cccdlflags='-DPIC -fPIC', lddlflags='-shared  -L/usr/local/lib'

Locally applied patches:
    

---
@INC for perl v5.8.5:
    /usr/local/lib/perl5/site_perl/5.8.5/mach
    /usr/local/lib/perl5/site_perl/5.8.5
    /usr/local/lib/perl5/site_perl
    /usr/local/lib/perl5/5.8.5/BSDPAN
    /usr/local/lib/perl5/5.8.5/mach
    /usr/local/lib/perl5/5.8.5
    .

---
Environment for perl v5.8.5:
    HOME=/home/mark
    LANG (unset)
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/usr/local/bin:/usr/local/sbin:/bin:/sbin:/usr/bin:/usr/sbin:/usr/X11R6/bin:/bin:/bin
    PERL_BADLANG (unset)
    SHELL=/usr/local/bin/bash

• [perl #32687] Encode::is_utf8 on tainted UTF8 string returns false by Mark Martinec
• [PATCH] Re: [perl #32687] Encode::is_utf8 on tainted UTF8 stringreturns false by Rafael Garcia-Suarez
• Re: [PATCH] Re: [perl #32687] Encode::is_utf8 on tainted UTF8 string returns false by Rafael Garcia-Suarez