Preface:
Was writing a script to replace single linebreaks in input to <br/> and multiple to </p><p class="content"> such as to parse user scribbling to very simple xhtml. Multiplatform linebreaks should be accepted.

There, I think I encountered very strange behaviour of PHP concerning octally escaped chars.

If I did something very very stupid, please don't hate me too much, I'm not too experienced w/ php. I however first showed this to a friend who is and he didn't know what it was either.

Short script:
------------------------
// parsed all newlines as single ones, resulting in a many <br/>s --
// two (!) for a linebreak, 1 for every added linebreak in the input
parseUserTextfield1($input) {
$parsed=preg_replace(array("/(\012\015|\012|\015)/","/(\012\015|\012|\015)(\012\015|\012|\015)+/"),
	       array('<br/>','</p><p class="content">'),
		       $input);

  return $parsed;
}

// parsed all newlines as multi ones, resulting in a many </p><p>s --
// so, only the first one seems to be matched...almost as if one linebreak in
// the browser seemed like multiple ones in the string
// browser is a mozilla 0.9.8 on the server -- shouldn't it just send \012
// using a linux-based system?

parseUserTextfield2($input) {
$parsed=preg_replace(array("/(\012\015|\012|\015)(\012\015|\012|\015)+/","/(\012\015|\012|\015)/"),
		       array('</p><p class="content">','<br/>'),
		       $input);

  return $parsed;
}

// curious thing: if i replace the linebreak expr. w/ BREAK as in:
function parseUserTextfield($input) {
  $parsed=preg_replace(array("/(BREAK)(BREAK)+/","/(BREAK)/"),
		       array('</p><p class="content">','<br/>'),
		       $parsed);

  return $parsed;
}
// everything works as expected
------------------------

List of Modules // ./configure - line (this simply is the SuSE7.3 i386 Cfg with security updates):

'./configure' '--prefix=/usr/share' '--datadir=/usr/share/php' '--bindir=/usr/bin' '--libdir=/usr/share' '--with-config-file-path=/etc' '--with-exec-dir=/usr/lib/php/bin' '--with-mysql=/usr' '--with-gd=yes' '--enable-gd-native-ttf' '--enable-gd-imgstrttf' '--with-tiff-dir=/usr' '--with-jpeg-dir=/usr' '--with-png-dir=/usr' '--with-xpm-dir=/usr/X11R6' '--with-ldap=yes' '--with-zlib=yes' '--with-bz2' '--with-gmp' '--with-xml' '--with-dom' '--with-ttf' '--with-t1lib' '--with-mcal=/usr' '--with-imap=yes' '--with-sablot' '--with-readline' '--with-ftp' '--with-ndbm' '--with-gdbm' '--with-mcrypt' '--with-gettext' '--with-mm' '--with-gd=yes' '--with-qtdom=/usr/lib/qt' '--enable-versioning' '--enable-yp' '--enable-bcmath' '--enable-trans-sid' '--enable-inline-optimization' '--enable-track-vars' '--enable-magic-quotes' '--enable-safe-mode' '--enable-sockets' '--enable-sysvsem' '--enable-sysvshm' '--enable-shmop' '--enable-calendar' '--enable-mbstring' '--enable-mbstr-enc-trans' '--enable-exif' '--enable-ftp' '--enable-memory-limit' '--enable-wddx' '--enable-filepro' '--enable-dbase' '--enable-ctype' '--disable-debug' '--enable-force-cgi-redirect' '--enable-discard-path' '--enable-sigchild' '--with-openssl' '--with-curl' '--with-swf=./dist/' '--with-imap-ssl' '--with-gd=yes' '--with-apxs=/usr/sbin/apxs' '--with-pgsql=/usr' '--with-snmp' 'i386-suse-linux'

Other Info:
None that I know of.

Backtrace:
No crash, no trace.