[perl #74114] when(scalar){} -> S_looks_like_bool: Assertion `o' failed.

# New Ticket Created by  Frank Wiegand 
# Please include the string:  [perl #74114]
# in the subject line of all future correspondence about this issue. 
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=74114 >


This is a bug report for perl from frank.wiegand@gmail.com,
generated with the help of perlbug 1.39 running under perl 5.12.0.


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

  % perl-5.10.1 -E 'when(scalar){}'
  Not enough arguments for scalar at -e line 1, near "scalar)"
  Execution of -e aborted due to compilation errors.

  % perl-5.12.0-RC3 -E 'when(scalar){}'
  perl-5.12.0-RC3: op.c:5272: S_looks_like_bool: Assertion `o' failed.
  Aborted

This regression has been introduced by the following commit (as git
bisect says):

5341b2b7ab11bc31f63ac7a675e74106418d0661 is the first bad commit
commit 5341b2b7ab11bc31f63ac7a675e74106418d0661
Author: Josh ben Jore <jjore@cpan.org>
Date:   Wed Sep 23 15:35:14 2009 -0700

    Fix when( scalar ... ) bug

    looks_like_bool should look past scalar(). Prior to this fix, saying
    scalar() caused the when() argument to be /not/ a boolean even if it
    reasonably was. Perhaps something like: when( scalar /$re/ ). I don't
    know any natural way someone is doing to use when(scalar ...) but it
    certainly seems like it was mistakenly left out.

:100644 100644 729c25f0aa87bcd25f8606bd70d852c6c67e1967 c3736fac0b76b2e4beaf755d5a628d4d71e129d3 M      op.c
:040000 040000 afe81091570f36d8e50f3513ec91f3f0f27b55f4 03acff2025d490e42f74d28599f1df3994becef1 M      t


Thanks, Frank

-----------------------------------------------------------------
---
Flags:
    category=core
    severity=low
---
Site configuration information for perl 5.12.0:

Configured by fw at Sat Apr  3 09:18:00 CEST 2010.

Summary of my perl5 (revision 5 version 12 subversion 0) configuration:
   
  Platform:
    osname=linux, osvers=2.6.32-trunk-amd64, archname=x86_64-linux
    uname='linux hal2 2.6.32-trunk-amd64 #1 smp sun jan 10 22:40:40 utc 2010 x86_64 gnulinux '
    config_args='-de -Dusedevel -DDEBUGGING=both -Doptimize=-g -Dcc=ccache gcc -Dld=gcc -Dprefix=/opt/perl/perl-5.12.0-RC3/ -Dmad'
    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='ccache gcc', ccflags ='-DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-g',
    cppflags='-DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include'
    ccversion='', gccversion='4.4.3 20100108 (prerelease)', 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='gcc', ldflags =' -fstack-protector -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib /lib64 /usr/lib64
    libs=-lnsl -lgdbm -ldb -ldl -lm -lcrypt -lutil -lc -lgdbm_compat
    perllibs=-lnsl -ldl -lm -lcrypt -lutil -lc
    libc=/lib/libc-2.10.2.so, so=so, useshrplib=false, libperl=libperl.a
    gnulibc_version='2.10.2'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
    cccdlflags='-fPIC', lddlflags='-shared -g -L/usr/local/lib -fstack-protector'

Locally applied patches:
    RC3

---
@INC for perl 5.12.0:
    /opt/perl/perl-5.12.0-RC3/lib/site_perl/5.12.0/x86_64-linux
    /opt/perl/perl-5.12.0-RC3/lib/site_perl/5.12.0
    /opt/perl/perl-5.12.0-RC3/lib/5.12.0/x86_64-linux
    /opt/perl/perl-5.12.0-RC3/lib/5.12.0
    .

---
Environment for perl 5.12.0:
    HOME=/home/fw
    LANG=de_DE.UTF-8
    LANGUAGE=
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/sbin:/usr/sbin:/home/fw/bin:/home/fw/bin:/usr/local/bin:/usr/bin:/bin:/usr/games
    PERL_AUTOINSTALL=--defaultdeps
    PERL_BADLANG (unset)
    PERL_EXTUTILS_AUTOINSTALL=--defaultdeps
    PERL_MM_USE_DEFAULT=1
    SHELL=/bin/zsh

• [perl #74114] when(scalar){} -> S_looks_like_bool: Assertion `o' failed. by Frank Wiegand
• Re: [perl #74114] when(scalar){} -> S_looks_like_bool: Assertion `o' failed. by Rafael Garcia-Suarez