From da6fc0f158fa9c76e5df675f57b57aa8c7a4b1b7 Mon Sep 17 00:00:00 2001
From: Shiro Kawai <shiro@acm.org>
Date: Wed, 2 Feb 2011 14:35:21 +0000
Subject: correct error estimation of floating point number reader


diff --git a/src/number.c b/src/number.c
index 9a7d8f8..d121edd 100644
--- a/src/number.c
+++ b/src/number.c
@@ -3543,6 +3543,7 @@ static double algorithmR(ScmObj f, int e, double z)
         case -1: /* d2 < y */
             if (Scm_NumCmp(m, SCM_2_52) == 0
                 && sign_d < 0
+                && k > -1074
                 && Scm_NumCmp(Scm_Ash(d2, 1), y) > 0) {
                 goto prevfloat;
             } else {
diff --git a/test/number.scm b/test/number.scm
index d397630..eb6d7eb 100644
--- a/test/number.scm
+++ b/test/number.scm
@@ -270,6 +270,12 @@
 (test* "flonum reader (minimum denormalized number -5.0e-324)" #t
        (let1 x (- (expt 2.0 -1074))
          (= x (string->number (number->string x)))))
+
+;; This hanged in 0.9.1.  See Jens Thiele's message in gauche-devel
+;; in Feb. 2011.
+(test* "flonum reader (minimum normalized number)" #t
+       (= (expt 2.0 (- 52 1074))
+          (string->number "2.2250738585072012e-308")))
        
 
 (test* "padding" '(10.0 #t) (flonum-test '1#))
-- 
1.7.3.4