Description:
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Although one of my regular expressions was compiled smoothly with php-5.3.3,  
I get the following exception message with php-5.3.4:

Exception: preg_match(): Compilation failed: unknown option bit(s) set at offset 0 



Test script:
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$symbol = "\xE2\x89\xA1";

$operands = 'a:3:{i:0;s:115:"/left\.operand'.$symbol.'(.?)(operand\.([^'.$symbol.']*)'.$symbol.'?([^'.$symbol.']*)?)?|right\.operand'.$symbol.'(.?)(operand\.([^'.$symbol.']*)'.$symbol.'?([^'.$symbol.']*)?)?/u";i:1;s:18:"left.operand'.$symbol.'⇒";i:2;N;}';

$op = unserialize( $operands );

$operand_pattern = $op[0];

$operand_index = $op[1];

$operand_matches = $op[2];

echo $operand_pattern, '<br />'.'<br / >';

echo $operand_index;

$operand_match = preg_match( $operand_pattern, $operand_index, $operand_matches );

Expected result:
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The string stored in the variable called 'operand_pattern' should be compiled as a valid regular expression.

Actual result:
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An exception is thrown.