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[ID 20010812.007] trivial function has wrong return value

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From:
mjd
Date:
August 12, 2001 09:51
Subject:
[ID 20010812.007] trivial function has wrong return value
Message ID:
20010812165149.18373.qmail@plover.com
This is a bug report for perl from mjd@plover.plover.com,
generated with the help of perlbug 1.33 running under perl v5.6.1.


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

What does this print?

        sub foo {
          my $x = 18;
          bar($x);
        }

        sub bar { }

        print foo();

Says "perlsub": "The return value of a subroutine is the value of the
last expression evaluated."  It seems strange to me that this isn't
qualified with "last expression evaluated by the sub", so that 
sub bar {}   always returns undefined, but that if that is OK with
you, it is OK with me.  Here, the last expression evaluated is the
computation of the argument $x, back in foo(), so bar() returns 18.

Now consider this:

        sub foo {
          my $x = 18;
          $x;
          bar();
        }

        sub bar { }

        print foo();

The last expression evaluated is still $x.  But bar() no longer
returns 18; instead, it returns undefined.



[Please do not change anything below this line]
-----------------------------------------------------------------
---
Flags:
    category=core
    severity=medium
---
Site configuration information for perl v5.6.1:

Configured by mjd at Mon Apr  9 13:10:50 EDT 2001.

Summary of my perl5 (revision 5.0 version 6 subversion 1) configuration:
  Platform:
    osname=linux, osvers=2.2.16, archname=i586-linux
    uname='linux plover 2.2.16 #5 wed sep 27 19:05:46 edt 2000 i586 unknown '
    config_args='-des'
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=undef use5005threads=undef useithreads=undef usemultiplicity=undef
    useperlio=undef d_sfio=undef uselargefiles=define usesocks=undef
    use64bitint=undef use64bitall=undef uselongdouble=undef
  Compiler:
    cc='cc', ccflags ='-fno-strict-aliasing -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-O2',
    cppflags='-fno-strict-aliasing -I/usr/local/include'
    ccversion='', gccversion='egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)', 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, usemymalloc=n, prototype=define
  Linker and Libraries:
    ld='cc', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib
    libs=-lnsl -lndbm -lgdbm -ldb -ldl -lm -lc -lposix -lcrypt -lutil
    perllibs=-lnsl -ldl -lm -lc -lposix -lcrypt -lutil
    libc=/lib/libc-2.1.3.so, so=so, useshrplib=false, libperl=libperl.a
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-rdynamic'
    cccdlflags='-fpic', lddlflags='-shared -L/usr/local/lib'

Locally applied patches:
    

---
@INC for perl v5.6.1:
    /usr/local/lib/perl5/5.6.1/i586-linux
    /usr/local/lib/perl5/5.6.1
    /usr/local/lib/perl5/site_perl/5.6.1/i586-linux
    /usr/local/lib/perl5/site_perl/5.6.1
    /usr/local/lib/perl5/site_perl/5.6.0/i586-linux
    /usr/local/lib/perl5/site_perl/5.6.0
    /usr/local/lib/perl5/site_perl
    .

---
Environment for perl v5.6.1:
    HOME=/home/mjd
    LANG (unset)
    LANGUAGE (unset)
    LC_ALL=POSIX
    LD_LIBRARY_PATH=/lib:/usr/lib:/usr/X11R6/lib
    LOGDIR (unset)
    PATH=/home/mjd/bin:/usr/local/bin:/bin:/usr/bin:/usr/X11/bin:/usr/games:/sbin:/usr/sbin:/usr/local/bin/X11:/usr/local/bin/mh:/data/mysql/bin:/usr/local/bin/pbm:/usr/local/bin/ezmlm:/home/mjd/TPI/bin:/usr/local/teTeX/bin:/usr/local/mysql/bin
    PERL_BADLANG (unset)
    SHELL=/bin/bash


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