Wrong error message at $r->read (.. , 0)

[Reif Peter <ga...@adv.magwien.gv.at>]

1. Problem Description:

I have written a mod_perl request handler. It reads incoming POST-date
with:

sub handler {
	my $r = shift;

	# ...
	my $cnt = $r->read($buf, 0);
	# ...
}

My hope is, that when I use 0 as length parameter to read, it will read
everything. But it only produces the following line in error_log:

[Mon Jun 11 11:51:34 2007] [error] [client 10.52.153.18] The LENGTH
argument can't be negative at ...

I don't agree with this, 0 is not negative!

2. Used Components and their Configuration:

*** mod_perl version 2.000003

*** using
/magwien/perl-5.8/lib/vendor_perl/5.8.8/i386-linux-thread-multi/Apache2/
BuildConfig.pm

*** Makefile.PL options:
  MP_APR_CONFIG  => /magwien/bin/apr-1-config
  MP_APR_LIB     => aprext
  MP_APXS        => /magwien/sbin/apxs2.2
  MP_COMPAT_1X   => 1
  MP_DEBUG       => 1
  MP_GENERATE_XS => 1
  MP_LIBNAME     => mod_perl
  MP_TRACE       => 1
  MP_USE_DSO     => 1


*** The httpd binary was not found


*** (apr|apu)-config linking info

 -L/magwien/lib -laprutil-1 -lldap -llber -ldb-4.1 -lexpat
-L/magwien/postgres/lib
 -L/magwien/lib -lapr-1  -lpthread -ldl 



*** /magwien/perl-5.8/bin/perl -V
Summary of my perl5 (revision 5 version 8 subversion 8) configuration:
  Platform:
    osname=linux, osvers=2.4.21-47.elsmp,
archname=i386-linux-thread-multi
    uname='linux lxentw1.host.magwien.gv.at 2.4.21-47.elsmp #1 smp wed
jul 5 20:38:41 edt 2006 i686 i686 i386 gnulinux '
    config_args='-des -Doptimize=-O2 -g -march=i386 -mcpu=i686
-Dversion=5.8.8 -Dmyhostname=localhost -Dperladmin=root@localhost
-Dcc=gcc -Dcf_by=MA14 - ADV/EG1 -Dcf_email=rf-eg1@adv.magwien.gv.at
-Dinstallprefix=/magwien/perl-5.8 -Dprefix=/magwien/perl-5.8
-Darchname=i386-linux -Dvendorprefix=/magwien/perl-5.8
-Dsiteprefix=/magwien/perl-5.8
-Dinstallman1dir=/magwien/perl-5.8/man/man1
-Dman1dir=/magwien/perl-5.8/man/man1
-Dinstallman3dir=/magwien/perl-5.8/man/man3
-Dman3dir=/magwien/perl-5.8/man/man3 -Duseshrplib -Dusethreads
-Duseithreads -Duselargefiles -Dd_dosuid -Dd_semctl_semun -Di_db
-Ui_ndbm -Di_gdbm -Di_shadow -Di_syslog -Dman3ext=3pm -Duseperlio
-Dinstallusrbinperl=n -Ubincompat5005 -Uversiononly
-Dpager=/usr/bin/less -isr -Dd_gethostent_r_proto -Ud_endhostent_r_proto
-Ud_sethostent_r_proto -Ud_endprotoent_r_proto -Ud_setprotoent_r_proto
-Ud_endservent_r_proto -Ud_setservent_r_proto -Dinc_version_list=5.8.7
5.8.6 -Dscriptdir=/magwien/perl-5.8/bin'
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=define use5005threads=undef useithreads=define
usemultiplicity=define
    useperlio=define d_sfio=undef uselargefiles=define usesocks=undef
    use64bitint=undef use64bitall=undef uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='gcc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -fno-strict-aliasing
-pipe -Wdeclaration-after-statement -I/usr/local/include
-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -I/usr/include/gdbm',
    optimize='-O2 -g -march=i386 -mcpu=i686',
    cppflags='-D_REENTRANT -D_GNU_SOURCE -fno-strict-aliasing -pipe
-Wdeclaration-after-statement -I/usr/local/include -I/usr/include/gdbm'
    ccversion='', gccversion='3.2.3 20030502 (Red Hat Linux 3.2.3-56)',
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='gcc', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib
    libs=-lresolv -lnsl -lgdbm -ldb -ldl -lm -lcrypt -lutil -lpthread
-lc
    perllibs=-lresolv -lnsl -ldl -lm -lcrypt -lutil -lpthread -lc
    libc=/lib/libc-2.3.2.so, so=so, useshrplib=true, libperl=libperl.so
    gnulibc_version='2.3.2'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E
-Wl,-rpath,/magwien/perl-5.8/lib/5.8.8/i386-linux-thread-multi/CORE'
    cccdlflags='-fPIC', lddlflags='-shared -L/usr/local/lib'


Characteristics of this binary (from libperl): 
  Compile-time options: MULTIPLICITY PERL_IMPLICIT_CONTEXT
                        PERL_MALLOC_WRAP USE_ITHREADS USE_LARGE_FILES
                        USE_PERLIO USE_REENTRANT_API
  Built under linux
  Compiled at Feb 21 2007 17:49:27
  %ENV:
    PERL_BADLANG="0"
    PERL_LWP_USE_HTTP_10="1"
  @INC:
    /magwien/perl-5.8/lib/site_perl/5.8.8/i386-linux-thread-multi
    /magwien/perl-5.8/lib/site_perl/5.8.7/i386-linux-thread-multi
    /magwien/perl-5.8/lib/site_perl/5.8.6/i386-linux-thread-multi
    /magwien/perl-5.8/lib/site_perl/5.8.8
    /magwien/perl-5.8/lib/site_perl/5.8.7
    /magwien/perl-5.8/lib/site_perl/5.8.6
    /magwien/perl-5.8/lib/site_perl
    /magwien/perl-5.8/lib/vendor_perl/5.8.8/i386-linux-thread-multi
    /magwien/perl-5.8/lib/vendor_perl/5.8.7/i386-linux-thread-multi
    /magwien/perl-5.8/lib/vendor_perl/5.8.6/i386-linux-thread-multi
    /magwien/perl-5.8/lib/vendor_perl/5.8.8
    /magwien/perl-5.8/lib/vendor_perl/5.8.7
    /magwien/perl-5.8/lib/vendor_perl/5.8.6
    /magwien/perl-5.8/lib/vendor_perl
    /magwien/perl-5.8/lib/5.8.8/i386-linux-thread-multi
    /magwien/perl-5.8/lib/5.8.8
    .

*** Packages of interest status:

Apache2            : -
Apache2::Request   : -
CGI                : 3.15
ExtUtils::MakeMaker: 6.30
LWP                : 5.803
mod_perl           : -
mod_perl2          : 2.000003


3. This is the core dump trace: (if you get a core dump):

  [CORE TRACE COMES HERE]

This report was generated by /magwien/perl-5.8/bin/mp2bug on Mon Jun 11
08:59:27 2007 GMT.