A quiet week with a bit of action at many corners of Perl development,
including some shiny new ones like Lamp. Improvement to docs and
threads on Switch, Module::Build modules are among
the discussion themes.
The last summary mentioned bug #37710 about a failed require
succeeding in a second time. Rafael Garcia-Suarez pointed this
is fixed in bleadperl and
Yitzchak Scott-Thoennes noticed the bug goes back
to 5.6.1 through current maint.
Rick Delaney entered the discussion to say the fix never made into maint
because of the introduction of the new semantic that
an undef value for an entry in %INC means the module failed to compile.
Rick mumbled on the unfortunate passing of the
corresponding change to L<perlfunc/require>
which actually shows implementation details in blead but not in 5.8.
http://xrl.us/izox
Andreas Koenig opened RT ticket #37713 to warn about Safe.pm,
which fails miserably with modules like POSIX, version, and others.
Even when no opcode restriction is made, examples like the one below
fails with blead and even worse with 5.8.7.
perl -le '
use Safe;
use Opcode;
my $comp = Safe->new;
my $opset = Opcode::full_opset;
$comp->permit($opset);
$comp->reval("use version; \$VERSION = qv(q{1.0.3}); print \$VERSION");
print $@ if $@;
'
Undefined subroutine &version::qv called at (eval 2) line 1.
Yves Orton remembered Tim Bunce declared Safe.pm to be a failed experiment and
wondered which is the current status of the module now that Raphael owns it.
Rafael answered he continues to fix things, backport the changes to CPAN
and thought this issue should be fixed.
http://xrl.us/izoy
Jim Cromie came back this week to polish its previous RFC patch based on Nicholas Clark's feedback. Jim concentrated on the idea of having arena-size per sv-type and included comments/docs for posterity, say, posterior maintenance. Later, Nicholas Clark pointed some confusion in the patch and kept waiting for Jim's answers.
http://xrl.us/izo2
Pod::Perldoc and Localized Docs Enrico Sorcinelli, one of the authors of POD2::IT, a project
to translate Perl man pages into Italian, proposed again
a patch against Pod::Perldoc to support viewing translated pods.
Rafael Garcia-Suarez applied to bleadperl the patch.
Enrico noticed POD2::FR just started, Portuguese fellows announced
POD2::PT shortly, and there is also a little POD2::LT for Lithuanian.
This may become a trend.
http://xrl.us/izo3
Sébastien Aperghis-Tramoni triggered a discussion asking about the convenience
of a patch to POD files setting up a consistent pattern in the formatting
of functions, modules, variables, and others. Andy Lester suggested
Sébastien to have a go, see the reaction and go from there.
Rafael Garcia-Suarez and others remembered it could be a good idea taking into
account the differences in rendering
in POD formatters, since pod2text (via perldoc), pod2html to
the custom formatters in sites like search.cpan.org and perldoc.perl.org.
After a suggestion by David Landgren, Sébastien's patch
which touched perlstyle.pod adopted the use of F<> for
files, C<> for generally anything that can be considered part of
code and B<> for command names. I think it basically
sums up to being simple as POD already is, which doesn't preclude
POD formatters to be clever and improved.
The patch was applied after a few minor fixes.
http://xrl.us/izo4
Michele Dondi opened ticket #37722 to report how weird
can be the interaction of concat and magic in tie()d
variables. Robin Houston summed it up to the bit of code
sub TIESCALAR { bless {} }
sub FETCH { shift()->{i} ++ }
tie $h, "main";
print $h.$h;
which may output "00" rather than "01" and posted a patch. Rafael Garcia-Suarez noticed the patch broke the warning test case
$ ./perl -we '$x.=$x'
which should report a use of uninitialized value error. On the grounds of a comment by Dave Mitchell on Michele's finding, Rafael conceded the behavior was not really a bug but the undefined result of execution order in expressions involving side-effects. Robin Houston insisted it could not be that difficult to fix, and tweaked the patch that now provides a left-to-right order on evaluation of subexpressions. The change has been applied as #26192.
Michele's finding
http://xrl.us/izo5
Robin's approach
http://xrl.us/izo6
Joshua Juran started a thread by posting some test results from the starting Lamp port for perl 5.6.1. Nicholas Clark curiously asked what led Joshua to elect 5.6.1 as a departing point rather than 5.6.2 or even better 5.8.something. Joshua explained he started working from Chris Nandor's MacPerl codebase, which is at 5.6.1 and promised to leave 5.6 behind as soon as he gets tests passing, approaching 5.8.x or blead. Rafael Garcia-Suarez suggested that, by starting at 5.6.2, Joshua's changes could be incorporated in this or in MacPerl branch. Joshua pointed that Lamp, a project for a Mac-hosted unix-like environment is similar in spirit to Cygwin and will hopefully have more in common with standard Perl than with MacPerl.
Joshua's test results
http://xrl.us/izo7
The Lamp project URL
http://sourceforge.net/projects/lamp/
Jan Dubois appreciated the analysis by Thomas Kratz (in ticket #37708)
about issues with socket-related declarations on Win32 whether
winsock2.h or winsock.h is included. The problem being that
Perl compiles using winsock2.h but perl.h includes winsock.h
leading to wrong winsock 1.1 constants and errors due to
redefined structs. Jan considered the best way to do it, avoiding
the breakage of existing modules, which may not need to know about
this and neither want it. H.Merijn Brand applied Jan's patch
as change #26189.
http://xrl.us/izo8
Module::Build Issues on Win32 A long thread started with a RT report on problems building PathTools
on Win2K
which was forwarded by Ken Williams to the list. Yves Orton spotted
that it was a Module::Build thing, related to the fact
that you can't unlink a DLL that is loaded into the memory.
ExtUtils::MakeMaker works around the issue because
it does the install via make so it
doesn't need to load anything that it might be installing over.
Yves suggested Module::Build on Win32 should produce a Build.bat
rather than a Build perl script, which would allow a more
Unixy behavior. Yves, Ken and Randy Sims discussed some
issues involving what should force the user to rerun Build.PL
and, while on this, Randy produced a patch to ExtUtils::CBuilder
to fix an encountered issue. The original case was made to work
and more permanent solutions to Module::Build on Win32
should be near (besides the recommendation to use another OS).
http://xrl.us/izo9
SWASHGET in XS This week, Sadahiro Tomoyuki thought it would be a good idea to speedup the retrieval of Unicode properties and transliterations mappings, which was done by the pure perl method SWASHGET. He rewrote SWASHGET in XS, which was welcome and commented by Dave Mitchell, Tels and Steve Peters. By the end of the week, an improved patch was already commited to blead.
http://xrl.us/izpa
Switch Boy Offer Kaye opened a can of worms when he did the simple question
of whether the bug #5607 in Switch had any chance to be fixed.
Ronald J. Kimball explained how
the issue of an unbalanced "/" causing a fatal error under
use Switch is due to the source filter nature of the module
and the small probability of a fix due to technical constraints.
David Landgren pointed Damian's module was always meant to
be an experiment and not for production purposes. There ensued
some discussion about the unpredictibility of source-filtered
modules, the requirements for a module to enter the core
and the possibilities of doing the opposite, removing a module from core.
Ah, and there were some advertisement on the DOR operator.
http://xrl.us/izpb
PathTools 3.14 in maint Ken Williams reflected with Nicholas Clark about the
alternatives to merge PathTools 3.14 to maint,
after the change that fixed absrel($x, $x) to
return curdir() and which is backwards incompatible
from the point of view of who risked to depend on
this buggy behavior.
http://xrl.us/izpc
Craig Berry wrote to say how the simplest command line piping in a threaded build of bleadperl on VMS now emits errors:
$ perl -e "print 'ok';" | exit
panic: free from wrong pool.
panic: free from wrong pool during global destruction.
%C-F-EBADF, bad file number
On VMS, command-line piping is implemented by Perl itself, and such pipe is opened before any thread context has been initialized. The problem is a check to yelp when deallocating from a different thread than the one which did the allocation and the no context case actually falls into this trap. To Rafael Garcia-Suarez, it looks like this check should be bypassed, which can help also applications that embed a perl interpreter.
http://xrl.us/izpd
Robin Houston started an effort to implement
the switch construct in core (in manner which is
as-compatible-as-possible with Switch.pm by Damian Conway)
and called for feedback on his initial proposal, with
replies by Rafael Garcia-Suarez, Dave Mitchel, Nicholas
Clark and Damian Conway.
http://xrl.us/izpe
This week started with the count of 1517 open RT tickets.
Robert Spier and the Bug summary
http://xrl.us/izpf
Perl RT just now
http://rt.perl.org/rt3/NoAuth/perl5/Overview.html
valgrind finding from blead
Following on Steve Peters trying to guess the source of
the leak in a sympathetic bit of code Jarkko Hietaniemi
posted, Jarkko delved into the gory combination that was
causing the problem: His latest conclusions point to
problems with the approach of determining whether $`, $&,
$' were found , the corresponding PL_sawampersand
and the eluding problem of how we can foresee what eval
is going to do to us. With a bit more of investigation,
Jarkko is yet not convinced he really found the guilty part.
http://xrl.us/izpg
Fighting Compilers Again Steve Hay reported how change #26152 ("All that can be in the first switch statement ofsv_upgrade is now") broke the windows build using VC++ 6. Steve and Nicholas Clark worked out a fixing change (concerning the use of unary minus to unsigned types), which, despite Nicholas' hopes, produces no errors but a bunch of warnings in VC++ 6, 7 and Borland.
http://xrl.us/izph
Thread Failures due to Interleaved Output H.Merijn Brand got fixed a problem causing thread failures on AIX (and others) caused by interleaved output.
http://xrl.us/izpi
libnet 1.19 on HP-UX on Perl 5.6.0
Yves Orton reported how he has met with core dumps while building
libnet 1.19 on HP-UX on Perl 5.6.0 and asked for any
recommendations. H.Merijn Brand brought some clues and
made a lot of questions to help diagnosing the problem, which
basically pointed to the non-root status of Yves, missing
installed patches, and issues with trusted HP-UX systems,
the beginning of perl 5.6 and outdated software.
Yves Orton's woes
http://xrl.us/izpj
Recent perl builds for HP-UX can be found here
http://mirrors.develooper.com/hpux/
GDBM_file realloc failures
On a threads-enabled perl, Rafael Garcia-Suarez noticed the tests
ext/GDBM_File/t/gdbm.t and lib/Memoize/t/tie_gdbm.t were
failing with the message:
panic: realloc from wrong pool
Rafael proposed a patch which reconciled the trouble due to memory alloc'd by libgdbm and realloc'd by perl. It was applied as change #26193 to bleadperl.
http://xrl.us/izpk
Where is Perl_do_open?
Stas Bekman noticed blead @ 26185 broke mod_perl2 after a
problem to find out Perl_do_open function. Rafael Garcia-Suarez
explained Perl_do_open now lives in mathoms.c and the
do_open macro in perl.h is the way to go. Stas' issues
revealed a bug in that Perl_do_open should be visible anyway
unless -DNO_MATHOMS were used. Stas did it by dropping the
Perl_ prefix on do_open/do_close.
http://xrl.us/izpm
Can't reset %ENV on VMS
John Malmberg noticed t/op/array.t and t/op/pat.t failed
on VMS because the test scripts call reset 'X', and
perl can not reset %ENV hash values on VMS.
http://xrl.us/izpn
http://xrl.us/izpo
Trouble with for (reverse @array)
Chris Duryee opened RT ticket #37725 to tell about
a segfault on a script using a for (reverse @array)
construction. Dave Mitchell found the bug to be due to
an optimization error to handle this very construction
and fixed the problem. After this, the one-liner
perl -e '$a[3] = 1; $i = 3; for my $x (reverse @a) { $x = $i-- }; print "@a"'
prints "0 1 2 3" instead of "1 0".
http://xrl.us/izpp
Sort subs can now be recursive Robin Houston fixed perlfunc.pod raising the limitation that sort subs may not be recursive, thanks to the sort/multicall patch worked out in the last weeks.
http://xrl.us/izpq
Version Check Failures due to locale
In ticket #37714, "dakkar" showed how version checks can made
to fail when a locale is in effect due to conversions of float
to strings. John Peacock explained how it is happening in maint and
blead and will do some research to make version comparisons
independent of locales.
http://xrl.us/izpr
VMS Issues with __FILE__ assuming UNIX Pathnames
John E. Malmberg pointed ext/List/Util/t/p_tainted.t assumes
__FILE__ returns a Unix pathname, which called for a fix on VMS.
On John's question about where __FILE__ is set, Rafael Garcia-Suarez
disclosed the relevant points in code. There remained some uncertainty
about the adequacy of John's fix, which should be hammered by
the discussion among Rafael, John and Craig A. Berry.
http://xrl.us/izps
Tk Compatibility
Gisle Aas pointed how Tk programs segfault when tried
with blead and wondered when it happened. Gisle also reminded
of changes needed to be applied for compiling and running
Tk in the perl-5.8.x branch.
http://xrl.us/izpt
perlce Touches Vadim Konovalov keeps on with the work on the WinCE port of Perl. This time, his patch touches some compilation bits and update explanations, renaming ./wince/README.perlce to ./README.ce.
http://xrl.us/izpu
perlpod.pod and =encoding
Yves Orton noticed perlpod.pod omits the new =encoding
directive from its "currently supported directive list"
and made it right.
http://xrl.us/izpv
Fast IS_UTF8_CHAR() for EBCDIC
A couple of weeks ago, it was noticed EBCDIC platforms UTF8
handling was broken, which Sadahiro Tomoyuki promptly fixed -
the guilty part was found to be on a change to speedup IS_UTF8_CHAR.
This week, Jarkko Hietaniemi tried to redeem himself with
a patch to bring the IS_UTF8_CHAR() speedup to (UTF-)EBCDIC
platforms and called for feedback from people which have
access to EBCDIC platforms.
http://xrl.us/izpw
char (un)signedness in Tru64 Jarkko Hietaniemi grew bored of the wrong guesses of Configure in Tru64 about the stdio char signedness, showed how funky Tru64 can be and implemented a workaround.
http://xrl.us/izpx
Cygwin Wrong Pools Yitzchak Scott-Thoennes found in cygwin/cygwin.c the bug which caused messages like the one below in Cygwin builds and fixed it.
panic: free from wrong pool at lib/lib_pm.PL line 6.
http://xrl.us/izpy
Where's the summary?, you may have asked, or worse you didn't even missed it. "What happened to professionalism? What about deadlines? I've had a cold. The cats ate my homework." And before you say I stole Piers Cawley's line, I just borrowed him the cats. Anyway, here's another better-late-than-never summary brought to you by Adriano Ferreira.
Information concerning bugs referenced in this summary (as #nnnnn) may be viewed at http://rt.perl.org/rt3/Ticket/Display.html?id=nnnnn
Information concerning patches to maint or blead referenced in this summary (as #nnnnn) may be viewed at http://public.activestate.com/cgi-bin/perlbrowse?patch=nnnnn
Weekly summaries are published on http://use.perl.org/ and posted on a mailing list, (subscription: perl5-summary-subscribe@perl.org ). The archive is at http://dev.perl.org/perl5/list-summaries/ . Corrections and comments are welcome.
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