Re: Perl, abs_path from Version 5.10.1-1 to 5.10.1-2 changed behaviour (no longer uses fast_path?)

[Reini Urban]

Thorsten Gunkel schrieb:

Hi *,
I have a perl script, which stopped working, when I recently updated cygwin
to 1.7.

Here is a small demo script which shows the problem. It just calls abs_path()
with different values and prints the output. It would be great if anyone
could confirm that they also see this behaviour.


#!/bin/env perl

use strict;
use Cwd 'abs_path';

abs_path_WITHDEBUG(".");
abs_path_WITHDEBUG("C:\\");
abs_path_WITHDEBUG("C:\\Program Files\\");
abs_path_WITHDEBUG("C:\\Does Not Exist\\");
exit;

sub abs_path_WITHDEBUG
{
   my $pPath = shift;
   my $result_path=abs_path($pPath);
   print "Test: \n PrePath={".$pPath."}\nPostPath={".$result_path."}\n\n";
   return $result_path;
}



When called with current Perl Version 5.10.1-2 it shows this output:
Test:
  PrePath={.}
PostPath={/tmp}

Test:
  PrePath={C:\}
PostPath={/tmp/C:\}<--- broken

Test:
  PrePath={C:\Program Files\}
PostPath={/tmp/C:\Program Files\}<--- broken

Test:
  PrePath={C:\Does Not Exist\}
PostPath={/tmp/C:\Does Not Exist\}<--- broken

Please notice, that the Windows path is justed added to the current
Unix path (which results in a broken path)


When I manually downgrade Perl to Version 5.10.1-1 it shows this output:
Test:
  PrePath={.}
PostPath={/tmp}

Test:
  PrePath={C:\}
PostPath={/cygdrive/c}

Test:
  PrePath={C:\Program Files\}
PostPath={/cygdrive/c/Program Files}

C:\Does Not Exist\: No such file or directory at ./demo.pl line 20

Here I get the correct Unix path in all cases.

The difference seems to be in Cwd.pm:

diff -u -U5 Cwd.pm*
--- Cwd.pm_old  2010-01-12 15:37:19.718007800 +0100
+++ Cwd.pm_new  2010-01-12 15:46:32.159043400 +0100
@@ -303,11 +303,11 @@
     cygwin =>
     {
      getcwd             =>  'cwd',
      fastgetcwd         =>  'cwd',
      fastcwd            =>  'cwd',
-    abs_path           =>  'fast_abs_path',
+#   abs_path           =>  'fast_abs_path',
      realpath           =>  'fast_abs_path',
     },

     epoc =>
     {
@@ -817,8 +817,8 @@
  *abs_path = \&_perl_abs_path unless defined&abs_path;
  *getcwd = \&_perl_getcwd unless defined&getcwd;

  # added function alias for those of us more
  # used to the libc function.  --tchrist 27-Jan-00
-*realpath = \&abs_path;
+*realpath = \&abs_path unless defined&realpath;

  1;

So abs_path used to point to fast_abs_path, but does not longer for Cygwin?
When I use fast_abs_path instead of abs_path in my test script it works for
both perl versions 5.10.1-1 and 5.10.1-2. What was wrong with fast_abs_path?
Should I just replace abs_path to fast_abs_path?

Yes please, until we come up with a satisfactory solution for all problems.

It was caused by a patch request from Eliott Moss
http://sourceware.org/ml/cygwin/2009-12/msg00506.html for svk,
which caused no regressions in the tests.

I'll talk to Stefan Müller to add such tests to the PathTools package.
--
Reini Urban
http://phpwiki.org/  http://murbreak.at/

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