Restore the use of system isnan() that was removed by

check-in [ea748edecb261f2b].  See
[forum:/forumpost/d7c530ac587f59e6|forum thread d7c530ac587f59e6].

FossilOrigin-Name: b3cfe23bec0b95ca673802526704200e2396df715fdded72aa71addd7f47e0e1

1 files changed, 11 insertions, 1 deletions

diff --git a/src/util.c b/src/util.c
index 2d1c64ad1..44c0195ca 100644
--- a/src/util.c
+++ b/src/util.c
@@ -60,11 +60,21 @@ int sqlite3FaultSim(int iTest){
 #ifndef SQLITE_OMIT_FLOATING_POINT
 /*
 ** Return true if the floating point value is Not a Number (NaN).
+**
+** Use the math library isnan() function if compiled with SQLITE_HAVE_ISNAN.
+** Otherwise, we have our own implementation that works on most systems.
 */
 int sqlite3IsNaN(double x){
+  int rc;   /* The value return */
+#if !SQLITE_HAVE_ISNAN && !HAVE_ISNAN
   u64 y;
   memcpy(&y,&x,sizeof(y));
-  return IsNaN(y);
+  rc = IsNaN(y);
+#else
+  rc = isnan(x);
+#endif /* HAVE_ISNAN */
+  testcase( rc );
+  return rc;
 }
 #endif /* SQLITE_OMIT_FLOATING_POINT */