Add protection from weirdness while scaling the mantissa to an integer.

diff --git a/Objects/floatobject.c b/Objects/floatobject.c
index 5f42ca57b3f60f901fa8c318b0ed41300d182d0e..ca05f0da1614793cf41bd56534d2da9a3c1bb798 100644 (file)
--- a/Objects/floatobject.c
+++ b/Objects/floatobject.c
@@ -1159,6 +1159,7 @@ float_as_integer_ratio(PyObject *v, PyObject *unused)
        double self;
        double float_part;
        int exponent;
+       int i;
 
        PyObject *prev;
        PyObject *py_exponent = NULL;
@@ -1198,16 +1199,21 @@ float_as_integer_ratio(PyObject *v, PyObject *unused)
        float_part = frexp(self, &exponent);    /* self == float_part * 2**exponent exactly */
        PyFPE_END_PROTECT(float_part);
        
-       while (float_part != floor(float_part)) {
+       for (i=0; i<300 && float_part != floor(float_part) ; i++) {
                float_part *= 2.0;
                exponent--;
        }
-       /* Now, self == float_part * 2**exponent exactly and float_part is integral */
+       if (i == 300) {
+               /* Could not convert mantissa to an integer */
+               Py_INCREF(Py_NotImplemented);
+               return Py_NotImplemented;
+       }       
+       /* self == float_part * 2**exponent exactly and float_part is integral */
 
        numerator = PyLong_FromDouble(float_part);
        if (numerator == NULL) goto error;
 
-       /* now self = numerator * 2**exponent exactly; fold in 2**exponent */
+       /* fold in 2**exponent */
        denominator = PyLong_FromLong(1);
        py_exponent = PyLong_FromLong(labs((long)exponent));
        if (py_exponent == NULL) goto error;
@@ -1216,8 +1222,7 @@ float_as_integer_ratio(PyObject *v, PyObject *unused)
        if (py_exponent == NULL) goto error;
        if (exponent > 0) {
                INPLACE_UPDATE(numerator,
-                              long_methods->nb_multiply(numerator,
-                                                        py_exponent));
+                              long_methods->nb_multiply(numerator, py_exponent));
                if (numerator == NULL) goto error;
        }
        else {