From 1e48c71b96282adf4c4a549077261c6c2ccbd715 Mon Sep 17 00:00:00 2001
From: Scott MacVicar <scottmac@php.net>
Date: Sun, 22 Aug 2010 08:01:34 +0000
Subject: [PATCH] Fix a bug where two doubles are equal but the maths operation
 makes it appear false.

Best example with INF where equals and identical produce different results.

<?php
var_dump(INF==INF);
var_dump(INF===INF);
---
 Zend/zend_operators.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/Zend/zend_operators.c b/Zend/zend_operators.c
index 3a89c9c71f..29db08011c 100644
--- a/Zend/zend_operators.c
+++ b/Zend/zend_operators.c
@@ -1410,8 +1410,12 @@ ZEND_API int compare_function(zval *result, zval *op1, zval *op2 TSRMLS_DC) /* {
 				return SUCCESS;
 
 			case TYPE_PAIR(IS_DOUBLE, IS_DOUBLE):
-				Z_DVAL_P(result) = Z_DVAL_P(op1) - Z_DVAL_P(op2);
-				ZVAL_LONG(result, ZEND_NORMALIZE_BOOL(Z_DVAL_P(result)));
+				if (Z_DVAL_P(op1) == Z_DVAL_P(op2)) {
+					ZVAL_LONG(result, 0);
+				} else {
+					Z_DVAL_P(result) = Z_DVAL_P(op1) - Z_DVAL_P(op2);
+					ZVAL_LONG(result, ZEND_NORMALIZE_BOOL(Z_DVAL_P(result)));
+				}
 				return SUCCESS;
 
 			case TYPE_PAIR(IS_ARRAY, IS_ARRAY):
-- 
2.40.0