Index: Lib/test/test_jy_internals.py
===================================================================
RCS file: /cvsroot/jython/jython/Lib/test/test_jy_internals.py,v
retrieving revision 2.2
diff -u -r2.2 test_jy_internals.py
--- Lib/test/test_jy_internals.py	10 Nov 2003 18:55:28 -0000	2.2
+++ Lib/test/test_jy_internals.py	19 Dec 2003 23:21:26 -0000
@@ -85,7 +85,26 @@
           for y in [0,255]:
             assert float((v+d)*256+y) == (((v+d)*256+y)*256).scaledDoubleValue(e)
             assert e[0] == 1        
-        
+
+class ExtraMathTests(unittest.TestCase):
+    def test_epsilon(self):
+        from org.python.core import ExtraMath
+        self.assertNotEqual(1.0 + ExtraMath.EPSILON, 1.0)
+        self.assertEqual(1.0 + (ExtraMath.EPSILON/2.0), 1.0)
+    def test_close(self):
+        from org.python.core import ExtraMath
+        self.assert_(ExtraMath.close(3.0, 3.0))
+        self.assert_(ExtraMath.close(3.0, 3.0 + ExtraMath.CLOSE))
+        self.assert_(not ExtraMath.close(3.0, 3.0 + 4.0*ExtraMath.CLOSE))
+    def test_closeFloor(self):
+        from org.python.core import ExtraMath
+        import math
+        self.assertEquals(ExtraMath.closeFloor(3.5), 3.0)
+        self.assertEquals(ExtraMath.closeFloor(3.0 - ExtraMath.EPSILON), 3.0)
+        self.assertEquals(
+          ExtraMath.closeFloor(3.0 - 3.0 * ExtraMath.CLOSE), 2.0)
+        self.assertEquals(ExtraMath.closeFloor(math.log10(10**3)), 3.0)
+
 def test_main():
     test_suite = unittest.TestSuite()
     test_loader = unittest.TestLoader()
@@ -93,6 +112,7 @@
         test_suite.addTest(test_loader.loadTestsFromTestCase(case))
     suite_add(WeakIdentityMapTests)
     suite_add(LongAsScaledDoubleValueTests)
+    suite_add(ExtraMathTests)
     run_suite(test_suite)
 
 if __name__ == "__main__":
Index: org/python/core/ExtraMath.java
===================================================================
RCS file: /cvsroot/jython/jython/org/python/core/ExtraMath.java,v
retrieving revision 2.3
diff -u -r2.3 ExtraMath.java
--- org/python/core/ExtraMath.java	28 Oct 2001 17:13:42 -0000	2.3
+++ org/python/core/ExtraMath.java	19 Dec 2003 23:21:26 -0000
@@ -6,7 +6,9 @@
  * A static utility class with two additional math functions.
  */
 public class ExtraMath {
-    static double LOG10 = Math.log(10.0);
+    public static double LOG10 = Math.log(10.0);
+    public static double EPSILON = Math.pow(2.0, -52.0);
+    public static double CLOSE = EPSILON * 2.0;
 
     public static double log10(double v) {
         return Math.log(v) / LOG10;
@@ -26,5 +28,31 @@
             double wv = w/v;
             return v * Math.sqrt(1.0 + wv*wv);
         }
+    }
+
+    /**
+     *  Are v and w "close" to each other?  Uses a scaled tolerance.
+     */
+    public static boolean close(double v, double w, double tol) {
+        if (v == w)
+        {
+            return true;
+        }
+        double scaled = tol * (Math.abs(v) + Math.abs(w))/2.0;
+        return Math.abs(w - v) < scaled;
+    }
+
+    public static boolean close(double v, double w)
+    {
+      return close(v, w, CLOSE);
+    }
+
+    /**
+     *  Returns floor(v) except when v is very close to the next number, 
+     *  when it returns ceil(v);
+     */
+    public static double closeFloor(double v) {
+        double floor = Math.floor(v);
+        return close(v, floor + 1.0) ? floor + 1.0 : floor;
     }
 }
Index: org/python/core/PyString.java
===================================================================
RCS file: /cvsroot/jython/jython/org/python/core/PyString.java,v
retrieving revision 2.61
diff -u -r2.61 PyString.java
--- org/python/core/PyString.java	11 Jul 2003 22:10:31 -0000	2.61
+++ org/python/core/PyString.java	19 Dec 2003 23:21:27 -0000
@@ -2040,7 +2040,7 @@
         }
         double power = 0.0;
         if (v > 0)
-            power = Math.floor(Math.log(v)/Math.log(10));
+            power = ExtraMath.closeFloor(ExtraMath.log10(v));
         //System.err.println("formatExp: "+v+", "+power);
         int savePrecision = precision;