Handle "NaN" and "Infinity" for input values.

I think NAN is already guaranteed to be there from Jan's work on NUMERIC,
 but perhaps HUGE_VAL needs some #ifndef's in the same place.
Should also include "-Infinity" as -HUGE_VAL sometime; not there yet.

src/backend/utils/adt/float.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/float.c,v 1.35 1998/11/29 01:57:59 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/float.c,v 1.36 1999/01/10 17:13:06 thomas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -249,8 +249,17 @@ float8in(char *num)
 
 	errno = 0;
 	val = strtod(num, &endptr);
-	if (*endptr != '\0' || errno == ERANGE)
+	if (*endptr != '\0')
+	{
+		if (strcasecmp(num, "NaN") == 0)
+			val = NAN;
+		else if (strcasecmp(num, "Infinity") == 0)
+			val = HUGE_VAL;
+		else if (errno == ERANGE)
+			elog(ERROR, "Input '%s' is out of range for float8", num);
+		else
 			elog(ERROR, "Bad float8 input format '%s'", num);
+	}
 
 	CheckFloat8Val(val);
 	*result = val;