added comment

diff --git a/Zend/zend_portability.h b/Zend/zend_portability.h
index f056b163388759d1430eb8cec01e6e581aaf4e61..73a4f3b96264c39b5f0299877e556eaa65ab0a27 100644 (file)
--- a/Zend/zend_portability.h
+++ b/Zend/zend_portability.h
@@ -394,6 +394,7 @@ char *alloca();
 #define ZEND_SECURE_ZERO(var, size) memset((var), 0, (size))
 #endif
 
+/* This check should only be used on network socket, not file descriptors */
 #ifdef ZEND_WIN32
 #define ZEND_VALID_SOCKET(sock) (INVALID_SOCKET != (sock))
 #else