[PHP-BUG] Bug #69588 [NEW]: Inconsistent numeric string comparison

From:             markus at malkusch dot de
Operating system: 
PHP version:      5.6.8
Package:          PHP Language Specification
Bug Type:         Bug
Bug description:Inconsistent numeric string comparison

Description:
------------
The manual says in "Comparison Operators":

> If [..] the comparison involves numerical strings, then each string is

> converted to a number and the comparison performed numerically.

That does explain why e.g. "10" == "0xa" evaluates to true. Now I would
expect that every other representation of 10 would do the same. It
doesn't for binary and octal representations. I.e "10" == "0b1010"
evaluates to false, the same for "10" == "012".

One could argue that numerical string is not defined. But then I would
expect that a string for which is_numeric() returns true would qualify
as a numerical string. is_numeric("012") does return true, but "012" ==
"10" not.

Test script:
---------------
<?php

var_dump(
    0b1010, "10" == "0b1010", // false
    012,    "10" == "012",    // false
    0xa,    "10" == "0xa",    // true
    1E+1,   "10" == "1E+1",   // true
    1e1,    "10" == "1e1",    // true
    10.0,   "10" == "10.0",   // true
    +10,    "10" == "+10"     // true
);

Expected result:
----------------
int(10)
bool(true)
int(10)
bool(true)
int(10)
bool(true)
double(10)
bool(true)
double(10)
bool(true)
double(10)
bool(true)
int(10)
bool(true)

Actual result:
--------------
int(10)
bool(false)
int(10)
bool(false)
int(10)
bool(true)
double(10)
bool(true)
double(10)
bool(true)
double(10)
bool(true)
int(10)
bool(true)

-- 
Edit bug report at https://bugs.php.net/bug.php?id=69588&edit=1
-- 
Try a snapshot (PHP 5.4):   https://bugs.php.net/fix.php?id=69588&r=trysnapshot54
Try a snapshot (PHP 5.5):   https://bugs.php.net/fix.php?id=69588&r=trysnapshot55
Try a snapshot (trunk):     https://bugs.php.net/fix.php?id=69588&r=trysnapshottrunk
Fixed in SVN:               https://bugs.php.net/fix.php?id=69588&r=fixed
Fixed in release:           https://bugs.php.net/fix.php?id=69588&r=alreadyfixed
Need backtrace:             https://bugs.php.net/fix.php?id=69588&r=needtrace
Need Reproduce Script:      https://bugs.php.net/fix.php?id=69588&r=needscript
Try newer version:          https://bugs.php.net/fix.php?id=69588&r=oldversion
Not developer issue:        https://bugs.php.net/fix.php?id=69588&r=support
Expected behavior:          https://bugs.php.net/fix.php?id=69588&r=notwrong
Not enough info:            https://bugs.php.net/fix.php?id=69588&r=notenoughinfo
Submitted twice:            https://bugs.php.net/fix.php?id=69588&r=submittedtwice
register_globals:           https://bugs.php.net/fix.php?id=69588&r=globals
PHP 4 support discontinued: https://bugs.php.net/fix.php?id=69588&r=php4
Daylight Savings:           https://bugs.php.net/fix.php?id=69588&r=dst
IIS Stability:              https://bugs.php.net/fix.php?id=69588&r=isapi
Install GNU Sed:            https://bugs.php.net/fix.php?id=69588&r=gnused
Floating point limitations: https://bugs.php.net/fix.php?id=69588&r=float
No Zend Extensions:         https://bugs.php.net/fix.php?id=69588&r=nozend
MySQL Configuration Error:  https://bugs.php.net/fix.php?id=69588&r=mysqlcfg