From b42eb01e5859a8554b91b8a7a3c42cbdf3917f9c Mon Sep 17 00:00:00 2001
From: unknown <kaa@polly.local>
Date: Sun, 29 Apr 2007 16:57:17 +0400
Subject: [PATCH] If isinf() is not available on a target platform, use our own
 imlementation via finite() and isnan(). If either of the last two is not
 available as well, use simple replacements which are platform-neutral, but
 slower than compiler intrinsics.

---
 include/my_global.h | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/include/my_global.h b/include/my_global.h
index f446c283d50..e9b371d8d30 100644
--- a/include/my_global.h
+++ b/include/my_global.h
@@ -784,13 +784,20 @@ typedef SOCKET_SIZE_TYPE size_socket;
 #define SSIZE_MAX ((~((size_t) 0)) / 2)
 #endif
 
+#ifndef HAVE_FINITE
+#define finite(x) (1.0 / fabs(x) > 0.0)
+#endif
+
+#ifndef HAVE_ISNAN
+#define isnan(x) ((x) != (x))
+#endif
+
 #if !defined(HAVE_ISINF)
 /* The configure check for "isinf with math.h" has failed */
 #ifdef isinf
 #undef isinf
 #endif
-/* Define isinf to never say that X is infinite */
-#define isinf(X)    0
+#define isinf(X) (!finite(X) && !isnan(X))
 #endif
 
 /* Define missing math constants. */