Hi, I have filed recent behavior change of == operator as bug #62097 https://bugs.php.net/bug.php?id=62097. (This is already marked as "Wont fix".)
Changes are: https://github.com/php/php-src/commit/9344bf193c6e35c8706923953f3e63bb01cc05ed https://github.com/php/php-src/commit/acd711685a592c52be200e248154283c6c49c9f8 This change is intended to fix Bug #54547 (https://bugs.php.net/bug.php?id=54547). But there are some backward incompatibility. I think that this change should not be applied to PHP 5.4. On PHP, when both operands are strings look like numbers, they are converted to numbers before comparison, for operator ==, >, <, and others. (Examples of strings look like numbers are: "123", "-56", "0120", "3.14", "1E5", "0xff") Old behavior, if converted numeric value fits into int, it is evaluated as a int. In other case it is evaluated as a float. (When zend_finite is false, operand is compared as string. But it is really rare case.) But changed new behavior, the case to compare as string is very extended: Converted number value exceed 2^63-1 in 64 bit, or 2^53-1 in 32-bit environment. This cause below incompatibility between PHP 5.4.3 and PHP 5.4.4RC2. ------------------------------------------------------------------- var_dump("9223372036854775807" == "9223372036854775808"); // 5.4.3 => bool(true) // 5.4.4RC2 => bool(false) [Good, fixed] // leading 0 var_dump("9223372036854775808" == "09223372036854775808"); // 5.4.3 => bool(true) // 5.4.4RC2 => bool(false) [incompatible] // leading space var_dump("9223372036854775808" == " 9223372036854775808"); // 5.4.3 nn => bool(true) // 5.4.4RC2 => bool(false) [incompatible] var_dump("12345678901234567890" == "12345678901234567890.0"); // 5.4.3 => bool(true) // 5.4.4RC2 => bool(false) [incompatible] var_dump("0xffffffffffffffffff" == "0xFFFFFFFFFFFFFFFFFF"); // 5.4.3 => bool(true) // 5.4.4RC2 => bool(false) [incompatible] var_dump("0xffffffffffffffffff" > "0xFFFFFFFFFFFFFFFFFF"); // 5.4.3 => bool(false) // 5.4.4RC2 => bool(true) [incompatible] ------------------------------------------------------------------- I think any backward incompatible change should not be introduced in major operators such as ==, anymore. But if behavior change is applied to string comparison operator, it should be a natural extension of current behavior; number-like string is compared as number, not as raw string. (e.g. canonicalize string as number way before string match.) -- OISHI Kazuo -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
