3 files changed, 85 insertions, 1 deletions
diff --git a/unix/configure b/unix/configure
index 099969b..697cf0d 100755
--- a/unix/configure
+++ b/unix/configure
@@ -16650,6 +16650,75 @@ done
 
 
 #--------------------------------------------------------------------
+# Check for support of isnan() function or macro
+#--------------------------------------------------------------------
+
+echo "$as_me:$LINENO: checking isnan" >&5
+echo $ECHO_N "checking isnan... $ECHO_C" >&6
+if test "${tcl_cv_isnan+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+
+    cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+#include <math.h>
+int
+main ()
+{
+
+isnan(0.0);			/* Generates an error if isnan is missing */
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext conftest$ac_exeext
+if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
+  (eval $ac_link) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest$ac_exeext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  tcl_cv_isnan=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+tcl_cv_isnan=no
+fi
+rm -f conftest.err conftest.$ac_objext \
+      conftest$ac_exeext conftest.$ac_ext
+fi
+echo "$as_me:$LINENO: result: $tcl_cv_isnan" >&5
+echo "${ECHO_T}$tcl_cv_isnan" >&6
+if test $tcl_cv_isnan = no; then
+
+cat >>confdefs.h <<\_ACEOF
+#define NO_ISNAN 1
+_ACEOF
+
+fi
+
+#--------------------------------------------------------------------
 # Darwin specific API checks and defines
 #--------------------------------------------------------------------
 
diff --git a/unix/configure.in b/unix/configure.in
index 82e68da..fb777b2 100644
--- a/unix/configure.in
+++ b/unix/configure.in
@@ -3,7 +3,7 @@ dnl	This file is an input file used by the GNU "autoconf" program to
 dnl	generate the file "configure", which is run during Tcl installation
 dnl	to configure the system for the local environment.
 #
-# RCS: @(#) $Id: configure.in,v 1.180 2008/03/28 17:31:47 dgp Exp $
+# RCS: @(#) $Id: configure.in,v 1.180.2.1 2008/03/31 17:21:18 dgp Exp $
 
 AC_INIT([tcl],[8.5])
 AC_PREREQ(2.59)
@@ -492,6 +492,18 @@ SC_ENABLE_LANGINFO
 AC_CHECK_FUNCS(chflags)
 
 #--------------------------------------------------------------------
+# Check for support of isnan() function or macro
+#--------------------------------------------------------------------
+
+AC_CACHE_CHECK([isnan], tcl_cv_isnan, [
+    AC_TRY_LINK([#include <math.h>], [
+isnan(0.0);			/* Generates an error if isnan is missing */
+], tcl_cv_isnan=yes, tcl_cv_isnan=no)])
+if test $tcl_cv_isnan = no; then
+    AC_DEFINE(NO_ISNAN, 1, [Do we have a usable 'isnan'?])
+fi
+
+#--------------------------------------------------------------------
 # Darwin specific API checks and defines
 #--------------------------------------------------------------------
 
diff --git a/unix/tclConfig.h.in b/unix/tclConfig.h.in
index 986c721..179f68a 100644
--- a/unix/tclConfig.h.in
+++ b/unix/tclConfig.h.in
@@ -289,6 +289,9 @@
 /* Do we have getwd() */
 #undef NO_GETWD
 
+/* Do we have a usable 'isnan'? */
+#undef NO_ISNAN
+
 /* Do we have <limits.h>? */
 #undef NO_LIMITS_H