"I do not know what crazy things people have done in code I cannot see. But people are creative in strange ways, and I cause them enough trouble already by incorporating changes with unintended behaviour changes." -- Nicholas Clark, on why it pays to be cautious.
Andreas König noted that there were eight modules in blead that had
more recent counterparts on CPAN, mentioning that one of them,
Text::Soundex, was intentionally neglected.
The reason for the neglect is that nobody cares about it any more, but since
it is in core, it cannot be removed. Those people who do need it know
enough to go to their local CPAN mirror and pick up the speedier XS-based
version. H.Merijn Brand thought that some effort should nonetheless be
made to keep blead and CPAN synchronised.
Steve Peters brought the most of listed modules up to date.
http://xrl.us/r7u3
Dave Mitchell went ballistic over the application of this patch, due to its gratuitous whitespace changes, as this makes it harder to see what the the true changes are. Similarly, people chasing down bugs in the future will stumble each time they have to traverse it.
Stop fiddling with the bloody whitespace http://xrl.us/r7u4
Jerry D. Hedden asked what the porters thought of overloading ""
in the threads module to return the thread identifier, since it
would make some constructs prettier.
John Peacock and Nicholas Clark didn't like the idea, as it seem
to admit the possibility of breaking programs that relied on the
existing behaviour (getting back a string like
threads=SCALAR(0x209e270c)).
Jerry, still not quite getting it, asked if that meant that the
possibility of incompatibility ruled out any chance of improvement.
So he floated the idea of an addition on the CPAN module that would
never be backported to maint, but that would be akin to a code
fork.
Gisle Aas disliked it as well. He had been down this track many years ago, and has since come to the conclusion that this sort of "feature" eventually winds up causing more problems that the ones it was supposed to solve.
Johnathon Stowe summed up the problem neatly, and it is this: no one can guarantee that there is no code anywhere that does something like
if ("$thread" =~ /^threads/)
regardless of whether this is a desirable way to test for an object being a thread. With that in mind (and this is really what the backwards compatibility game is all about), there was little chance that the patch would be applied. Since behaviour is being changed, regardless of what merit or value it has, new behaviour can only be activated by asking for it.
http://xrl.us/r7u5
Despite the arguments against the proposal, Jerry went ahead and
made the change. Rafaël declined to integrate it into blead.
Jerry finally admitted defeat, and said he'd add an import()
verb to activate the change.
http://xrl.us/r7u6
Which in fact, he did. Applied as change #28958.
And they all lived happily ever after, kthnx http://xrl.us/r7u7
regmatch() restructuring complete Dave "Leakbane" Mitchell announced that his restructuring work on
regmatch() was now complete. Now no more recursion fakery is
needed, all backtracking is now done via a single backtracking
state stack. Dave was quite pleased to see that the amount of
state required had been shrunk from 72 bytes down to 44 bytes (on
32-bit systems).
Dave posted the large comment that explains the matching strategy for we other mere mortals to ponder. Yves Orton was pleased as Punch, since he realised this would simplify the things he wants to implement.
Affairs of state http://xrl.us/r7u8
Andreas König noticed that change #28900 causes HTTP::Daemon
to fail, specifically, a slice of stat _ gets garbled.
The odd thing was that change #28900 was one of Yves's patches for the regular expression engine. Neither Yves nor Rafaël Garcia-Suarez could figure out why that would be, but Andreas was certain, postulating some weird side-effect.
It turns out to be a poor assumption in the HTTP::Daemon code,
which assumed that _ (the underscore filehandle) is lexically
scoped (which in fact, it never was). So if you call a subroutine
and then access it afterwards, it's possible that the subroutine
will have used it for its own purpose. And that's exactly what
happened here.
Yves was relieved, but thought about what he could do to minimise the impact in the future.
Action at a distance http://xrl.us/r7u9
John Peacock reported having worked on version objects in the
presence of locales, where commas may be used for decimal points instead
of the anglo-saxon period. The code was easy, (since Rafaël had done
most of the heavy lifting), but John was wondering how to test it. He
asked for a show of hands (off-list) to see who had the 'de_DE' locale
present on their machine.
H.Merijn Brand noted that he tended to delete all non-crucial locales from his machines, since localised software tended to enjoy installing their documentation in all the locales on the machine for which it had a corresponding version. This can lead to rampant disk space consumption, and even require reboots, should the software in question be kernel-related.
Jarkko Hietaniemi suggested setting up a list of all the locales in
the world that used non-period decimal points, and iterating over them
until one pops up on the machine running the tests. John already had
similar code that does this, so he promised to whip up a development
version of version, and get people to smoke it for a while and see
what comes out.
http://xrl.us/r7va
Data::Dumper might be faster now Nicholas Clark tweaked Data::Dumper slightly to reduce the amount
of realloc()s being performed. The results were quite surprising.
Andy Lester acquired the necessary commit bits to update the CPAN
version.
Dumpin' goodness http://xrl.us/r7vb
-std=c89 and -pedantic Jarkko and H.Merijn continued to work on this, getting to the stage where it was good enough to be applied.
http://xrl.us/r7vc
Yves Orton delivered a first cut at implementing named captures in Perl. This allows the following:
'falange' =~ /(?<end>....)$/ and print $+{end} # prints "ange"
This comes in very handy when you have lots of nested capturing
groups, since you no longer have to count parentheses, nor do you
have to renumber your $1, $2, $3, ... when you insert a
new capturing group somewhere in the middle.
H.Merijn Brand thought that this was so cool that it was nearly enough all by itself as being sufficient reason to upgrade Perl.
The thread became sidetracked into improvements for Johan
Vroman's makepatch program. After a number of suggestions
from Yves and Dr. Ruud, Johan promised to release a new version.
http://xrl.us/r7vd
Yves merged his and Dr. Ruud's patch into a single metapatch
for makepatch.
http://xrl.us/r7ve
FAIL(XF) linux 2.6.17-1.2187_FC5 [fedora] (i686/1 cpu) Steve Peters smoked a build with a recent gcc compiler and gouts of
oily black smoke poured out of the vents. Jarkko interpreted this as
meaning the gcc has become more aggressive in its ANSI conformance
checks. That's the good news. The bad news is that the code base uses
the non-ANSI long long datatype, for 64 bits of goodness. Jarkko
was hoping that there was some way to placate gcc over this minor
transgression.
Maybe if we slaughtered a chicken http://xrl.us/r7vf
Steve Peters reasoned that this bug had been fixed, but looking through the patches, could not determine which one was responsible.
http://xrl.us/r7vg
read, fork and exit mismatch file positions (#5999) The Solaris man page says it all: if you do I/O in a child process with the file descriptors inherited from the parent, you have to be very careful how the child exits, otherwise strange surprises await you.
Aaron Sherman wondered if there was a way of squirrelling the necessary information away somewhere, so that the child would do the right thing in this event. Steve Peters cautioned that no one had sat down and worked through all the delicate intricacies of fork-related issues, especially when one considers threads at the same time.
http://xrl.us/r7vh
Steve then returned to a regexp bug filed by Jeffrey Friedl, no less, and noted that the poor observed performance had been corrected due to Yves Orton's trie work.
Yves noted that this was indeed the case, yet Jeffrey's analysis of
the problem was indeed correct. There are a number of ways in which
an alternation can be dealt with by the engine, and these work more
or less efficiently depending on the pattern and the target (a bit
like an SQL query planner). It turns out that when non-capturing
parentheses (?:...) were added to the engine, the optimiser started
making bad decisions, such as the one noted by Jeffrey.
At first, Yves couldn't see an easy way to make this work without
introducing additional overhead. Hugo van der Sanden thought
that it might be worth examining end anchors and finite maximum
match widths as well. He thought that a number of anchor-related
optimisations have broken since the \A, \Z and \z anchors
were introduced, and by the same token that other new optimisations
are now possible.
Yves then discovered an cheap, fast, reliable solution to the problem.
Pick all three http://xrl.us/r7vi
File::Find has issues with symlinks (#40417) Rafaël tried out the supplied patch for this problem, but noted
that it broke three tests in blead's regression tests. He asked
for an updated patch (with more tests) to take this into account.
http://xrl.us/r7vj
Alex Davies filed a bug on the problem of Control-C causing core dumps on Windows. No takers for the moment, but Yves Orton mentioned this behaviour recently.
http://xrl.us/r7vk
Benjamin Carter showed how a small script with redo, eval
and @_ would crash regularly. Dave Mitchell believes the
underlying problem was fixed by change #24384.
next and redo didn't restore PL_curcop http://xrl.us/r7vm
Tasnim was running into problems building perl. Andy Dougherty suspected that there might be a problem with the config.sh file, and suggested that Tasnim delete the source tree and start afresh.
http://xrl.us/r7vn
Tasnim followed up with another bug report (#40454), but the porters didn't hear back from him after their suggestions were given
So maybe it works http://xrl.us/r7vo
MULTICALL (#40469) Tassilo von Parseval found a memory leak, and thought that
MULTICALL was responsible. No takers.
http://xrl.us/r7vp
glob misbehaviour regarding special characters and spaces (#40470) David Serrano found what he thought was a problem in glob with
files or directories that contain spaces. No takers, possibly because
everyone hates files and directories that contain spaces.
Curse those Redmond boys http://xrl.us/r7vq
8 more this week http://xrl.us/r7vr
http://rt.perl.org/rt3/NoAuth/perl5/Overview.html
Terry Glanfield demonstrated a nifty bug in Storable to show
that Storable::freeze([$r, $r]) doesn't work. Adam Kennedy asked
him to open a ticket on Storable's CPAN RT queue.
http://xrl.us/r7vs
Steve Hay noticed that threads tests were hanging in Win32
smokes again, and wondered if changes #28922 and #28923 had anything
to do with it.
http://xrl.us/r7vt
Dave Mitchell explained to Dave Rolsky that the 5.8 code for closures has a number of subtle bugs, and will probably always remain that way.
But wait until 5.10 http://xrl.us/r7vu
Paul Green updated the Stratus VOS files.
http://xrl.us/r7vv
Now that it has been ANSIfied, the zlib library can be build
with g++ .
http://xrl.us/r7vw
Alan Olsen pointed to a couple of threads on Perl Monks that dealt
with Exporter problems, suggesting that the problems raised
there, and the attendant solutions, should be included on the
Exporter documentation.
http://xrl.us/r7vx
Paul Marquess added some C++ goodness to List::Util .
http://xrl.us/r7vy
And Jarkko continued his own peculiar brand of compiler gymnastics.
http://xrl.us/r7vz
The One Laptop Per Child project no longer requires Perl. When you only have 500Mb of Flash memory to play with...
... every byte counts http://xrl.us/r7v2
This summary was written by David Landgren.
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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Re:On whitespace changes
kwilliams on 2006-10-12T23:30:03
Or, if the changelist number that did the reformatting is known, just skip over that changelist number when doing diffs. That helps when the formatting changes cross line boundaries (like moving braces to the next line, etc.) and the line-oriented diff algorithms are still too chatty.