This Week on perl5-porters (15-21 September 2003)

This Week on perl5-porters (15-21 September 2003)
  Those weeks, the perl 5 porters are in maintenance mood. Or in
  maintenance mode, if you prefer. Read about the progress made in the
  5.8.x and 5.6.x branches.

A strange error case in bleadperl
  Stas Bekman posted a code snippet that produces the fatal error
  "Modification of a read-only value attempted" with bleadperl, but not
  with perl versions <= 5.8.1. (Filed as bug #23803.) It can be reduced to :

      for("a") { for $x (1,2) { local $_="b"; s/(.*)/+$1/ } }

  This was the consequence of a previous bug fix. Rafael explained that in
  perl 5.9.0, any attempt at changing the value of a localized readonly
  magic scalar will fail with this error. Before, it used to silently do
  nothing, and the assignment $_="b" was a no-op : this could lead to
  difficult and well-hidden bugs. In bleadperl, readonlyness of magical
  scalars is now preserved when localisation occurs.

  But, will you say, where is the magic in the above snippet ? In fact, it
  appears that the substitution s/(.*)/+$1/ adds some magic to the
  scalar stored in $_. This kind of magic is used internally by the
  regular expression engine. Thus, one can say that the behaviour reported
  by Stas is an unfortunate side-effect of the implementation of regular
  expressions.

      http://xrl.us/tvu

Configure and gcc 3.4
  Enache Adrian, watchful on the portability front, forwards a mail from
  the gcc development mailing list. A change in gcc's behaviour in the 3.4
  development branch leads to breaking perl's Configure script ; more
  precisely, it breaks the way Configure tests for the existence of a
  function in the standard library.

  This was followed by a scary C wizardry thread. Enache provided a fix.

      http://xrl.us/tvv

In Brief
  Jarkko Hietaniemi released several snapshots of perl 5.8.1. The next
  release candidate approaches. Extensive tests have been done with
  mod_perl 1 and 2, and this uncovered several problems, both in mod_perl
  and in perl.

  Speaking about snapshots, Rafael released one of perl 5.6.2. It's OK on
  a large number of platforms ; adjustments are needed on Mac OS X and
  Cygwin at least. Rafael incremented the version number, so it reports
  itself as being 5.6.2.

  The bulk of the discussion focused on portability on various platforms
  -- mainly the non-Unix ones, VMS, OS/2, Windows and Cygwin. Peter
  Prymmer reported that perl now looks good on VMS 7.3-1, with no
  regression test failing.

  Ilya Zakharevich and Yves Orton reported a few bugs in Test::Harness.

  Stas Bekman noticed that with perl 5.8.1, if a socket gets closed by the
  server while printing to it, the client gets a SIGPIPE. It wasn't
  happening in perl 5.8.0 or earlier. (This is considered a feature, not a
  bug.)

  Michael Schwern released base.pm version 2.03, which fixes an obscure
  (and ancient) bug on attribute inheritance, when an intermediate class
  has no fields.

About this summary
  This week's summary was produced by Rafael Garcia-Suarez. Summaries are
  published weekly on http://use.perl.org/ and on a mailing list, which
  subscription address is [email protected]. Corrections
  and comments are welcome.