Description:
------------
Passing following UTF8 text thru 3rd line of the test script (i.e., 
preg_replace() function) causes an error in preg_replace function:

[post=0a /]

Whereas, passing following UTF8 text similarly causes no error:

[post=a0 /]

Problem seems to be caused only when the "=" is followed by an integer then 
followed by a letter.  I briefly tried other combinations without causing error.

Workaround is to replace third line of test script with this line (i.e., use the 
preg_replace_callback() instead of preg_replace()

$out = preg_replace_callback( '@\[p(?:ost){0,1}=(.{1,24})\ {0,}\/\]@Uiu', 
'debdcode_post', $i_html );




Test script:
---------------
$html_ours[0] = '@\[p(?:ost){0,1}=(.{1,24})\ {0,}\/\]@Uieu';

$html_oursr[0] = 'debdcode_post( $1 )'; // irrelevant, use any misc func that looks up post id in db

$out = preg_replace( $html_ours, $html_oursr, $i_html );

Expected result:
----------------
The general use is in a BBCODE-like parser for use in a FORUMS app.

What should happen:

In the source text (in UTF-8 format),

the string "[post=4ablahblah /]"

should be picked out of any given arbitrary input

by the preg_replace()

and then translated to a hyperlink

by the debdcode_post().  What is happening instead is the error in preg_replace, 
presumably from malformed UTF-8 or possibly a bug inside preg_replace when 
dealing with the particular character sequence "=<integer><letter(s) and/or 
integer(s)>.  Note that it's the "=" followed by an integer and then followed by 
at least one letter and/or more integers that triggers the error.  I hope this 
helps; thank you for looking.

Actual result:
--------------
Parse error: syntax error, unexpected T_STRING in 
/apath/Class/common_functions.inc(1405) : regexp code on line 1

Fatal error: preg_replace() [<a href='function.preg-replace'>function.preg-
replace</a>]: Failed evaluating code: debdcode_post( 4f30abfddc79595474000020 ) in 
<file:line>