Do not redefine zend_isnan if it is already defined.

diff --git a/Zend/acconfig.h b/Zend/acconfig.h
index 40a4c0590d8e6c3271400c55a4352fdf87a0a915..582d199f7a61ffb03f4f8100d2e62a781e1b5c71 100644 (file)
--- a/Zend/acconfig.h
+++ b/Zend/acconfig.h
@@ -63,6 +63,7 @@ int zend_sprintf(char *buffer, const char *format, ...);
 
 #include <math.h>
 
+#ifndef zend_isnan
 #ifdef HAVE_ISNAN
 #define zend_isnan(a) isnan(a)
 #elif defined(NAN)
@@ -72,6 +73,7 @@ int zend_sprintf(char *buffer, const char *format, ...);
 #else
 #define zend_isnan(a) 0
 #endif
+#endif
 
 #ifdef HAVE_ISINF
 #define zend_isinf(a) isinf(a)