Hi folks!

During my PHP development I encountered the bug described below.
It looks like a problem in the interpreter. I made a
little source example which reproduces the problem. It is
related to function parameters which are passed by reference,
e.g. function foo(&$a){ $a = 10; } 

Combined with include() statements, PHP seems to mix up the
Parameter signatures of functions defined in different files.
In some weird cases, it tells that the call (e.g. bar(3) ) 
of another function, e.g. function bar($b){ return $b + 10; } 
is not possible, because '3' would not be a reference. 

This is the good case. It becomes even more weird when passing
a reference, e.g. bar($x). Then PHP will probably crash with a page
fault.

I found out the following conditions for this bug to occur
(not necessarily complete nor totally correct):

1. 4 or more files are included via include().
2. At least 2 files perform a cyclic include with each other.
3. At least 2 files define different functions, one with
   a parameter passed by reference, the other without.
4. Another file calls the function without parameters passed
   by reference.

This must not always happen, but in my example (see below), 
it "works". The example will produce the following error message:
"Warning: Cannot pass expression as argument 1 by reference in c:\program\internet\apache\server1.3.4\htdocs\test\crash.php on line 8"

My actual workaround is not to use parameters passed by reference.

Perhaps one of you hardcore PHP developers wants to get into
this? Let me know if you find out something!

Regards,
Jens Fransson.

E-Mail: jens__26@yahoo.com



------BUG REPORT----------------------------------------------------------------
Classification: Reproducable Crash, Language related
Related to: Parameters passed by reference, include()
Workaround: Do not use Parameters passed by reference
--Platform information:--
PHP Version 3.0.6 (Win32, binary Distribution)
OS: Windows 98
Server: Apache 1.3.4 (Win32)
Database: MySQL Shareware (Win32) Ver 9.13 Distrib 3.21.29a-gamma, for Win95 (i586)
Hardware: Pentium MMX-233, 64 MB RAM
--------------------------------------------------------------------------------


The example for reproducing the bug consists of 5 files:
"crash.php" (The main file, load this into a browser)
"bricks.inc", "design.inc", "utility.inc", "dbdef.inc"


--------------------------------------------------------------------------------
START of Code files
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
START of File "crash.php"
--------------------------------------------------------------------------------
<?php

include("./dbdef.inc");
include("./utility.inc");
include("./design.inc");
include("./bricks.inc");

print(buildSuchUserDataTable("hallo", false, 0));
  
?>
--------------------------------------------------------------------------------
END of File "crash.php"
--------------------------------------------------------------------------------


--------------------------------------------------------------------------------
START of File "bricks.inc"
--------------------------------------------------------------------------------
<?php

if (!isset($bricks_inc)){  

  $bricks_inc = true;
  
  include("./dbdef.inc");
  include("./utility.inc");
  include("./design.inc");
  
  function buildSuchUserDataTable($userKennung, $useDatabase = true,
    $userData = 0, $buildOnlyRows = false, $colspanLeft = 1, $colspanRight = 1, 
    $databaseLink = 0){
  }

}  

?>
--------------------------------------------------------------------------------
END of File "bricks.inc"
--------------------------------------------------------------------------------


--------------------------------------------------------------------------------
START of File "design.inc"
--------------------------------------------------------------------------------
<?php

if (!isset($design_inc)){

  $design_inc = true;

}

?>
--------------------------------------------------------------------------------
END of File "design.inc"
--------------------------------------------------------------------------------


--------------------------------------------------------------------------------
START of File "utility.inc"
--------------------------------------------------------------------------------
<?php

if (!isset($utility_inc)){

  $utility_inc = true;

  
  function mkValid(&$variable, $default = "", $assignIfEmpty = false){
    if (!isset($variable)) $variable = $default;
    else if ($assignIfEmpty) {
      if ($variable == "") $variable = $default;
    }
  }
  
}

?>
--------------------------------------------------------------------------------
END of File "utility.inc"
--------------------------------------------------------------------------------


--------------------------------------------------------------------------------
START of File "dbdef.inc"
--------------------------------------------------------------------------------
<?php

if (!isset($dbdef_inc)){

  $dbdef_inc = true;

}
  
?>
--------------------------------------------------------------------------------
END of File "dbdef.inc"
--------------------------------------------------------------------------------


--------------------------------------------------------------------------------
END of Code files
--------------------------------------------------------------------------------


The example will NOT produce a Windows exception. I encountered this 
exception with the original code, which passed a variable, not a constant.
I think this case is of minor importance, so I only post this message.

-----START of text of the Windows exception message:-----
PHP verursachte einen Fehler durch eine ung?ltige Seite
in Modul KERNEL32.DLL bei 0177:bff7b983.
Register:
EAX=00000021 CS=0177 EIP=bff7b983 EFLGS=00010206
EBX=00000000 SS=017f ESP=006bfda8 EBP=006bfdb8
ECX=0046bd30 DS=017f ESI=013296f0 FS=3a47
EDX=bffc9490 ES=017f EDI=00000000 GS=0000
Bytes bei CS:EIP:
80 3e 04 74 0f 33 c0 50 50 50 68 05 00 00 c0 e8 
Stapelwerte:
0046c460 00442233 013296f0 00000005 006bfe38 0043e169 00000021 0044d638 00000005 0046bd50 00000001 00453024 0043de61 8165a618 0043de0b 0045301c 
-----END of text of the Windows exception message-----