Index: Include/longobject.h
===================================================================
--- Include/longobject.h	(révision 70631)
+++ Include/longobject.h	(copie de travail)
@@ -33,12 +33,12 @@
 PyAPI_DATA(int) _PyLong_DigitValue[256];
 
 /* _PyLong_AsScaledDouble returns a double x and an exponent e such that
-   the true value is approximately equal to x * 2**(SHIFT*e).  e is >= 0.
+   the true value is approximately equal to x * 2**e.
    x is 0.0 if and only if the input is 0 (in which case, e and x are both
    zeroes).  Overflow is impossible.  Note that the exponent returned must
    be multiplied by SHIFT!  There may not be enough room in an int to store
    e*SHIFT directly. */
-PyAPI_FUNC(double) _PyLong_AsScaledDouble(PyObject *vv, int *e);
+PyAPI_FUNC(double) _PyLong_AsScaledDouble(PyObject *vv, unsigned int *e);
 
 PyAPI_FUNC(double) PyLong_AsDouble(PyObject *);
 PyAPI_FUNC(PyObject *) PyLong_FromVoidPtr(void *);
Index: Objects/longobject.c
===================================================================
--- Objects/longobject.c	(révision 70631)
+++ Objects/longobject.c	(copie de travail)
@@ -676,8 +676,12 @@
 
 }
 
+/**
+ * Convert a long integer into result * 2^exponent. If exponent is
+ * bigger than INT_MAX, return -1.0 and raise an OverflowError.
+ */
 double
-_PyLong_AsScaledDouble(PyObject *vv, int *exponent)
+_PyLong_AsScaledDouble(PyObject *vv, unsigned int *exponent)
 {
 /* NBITS_WANTED should be > the number of bits in a double's precision,
    but small enough so that 2**NBITS_WANTED is within the normal double
@@ -723,10 +727,17 @@
 	}
 	/* There are i digits we didn't shift in.  Pretending they're all
 	   zeroes, the true value is x * 2**(i*PyLong_SHIFT). */
-	*exponent = i;
+	if (i > UINT_MAX / PyLong_SHIFT)
+		goto overflow;
+	*exponent = (unsigned long)i * PyLong_SHIFT;
 	assert(x > 0.0);
 	return x * sign;
 #undef NBITS_WANTED
+
+overflow:
+	PyErr_SetString(PyExc_OverflowError,
+		"Python int too large to convert to C double");
+	return -1.0;
 }
 
 /* Get a C double from a long int object. */
@@ -734,7 +745,7 @@
 double
 PyLong_AsDouble(PyObject *vv)
 {
-	int e = -1;
+	unsigned int e;
 	double x;
 
 	if (vv == NULL || !PyLong_Check(vv)) {
@@ -744,13 +755,8 @@
 	x = _PyLong_AsScaledDouble(vv, &e);
 	if (x == -1.0 && PyErr_Occurred())
 		return -1.0;
-	/* 'e' initialized to -1 to silence gcc-4.0.x, but it should be
-	   set correctly after a successful _PyLong_AsScaledDouble() call */
-	assert(e >= 0);
-	if (e > INT_MAX / PyLong_SHIFT)
-		goto overflow;
 	errno = 0;
-	x = ldexp(x, e * PyLong_SHIFT);
+	x = ldexp(x, e);
 	if (Py_OVERFLOWED(x))
 		goto overflow;
 	return x;
@@ -2714,7 +2720,8 @@
 {
 	PyLongObject *a, *b;
 	double ad, bd;
-	int failed, aexp = -1, bexp = -1;
+	int failed, exp;
+	unsigned int aexp, bexp;
 
 	CONVERT_BINOP(v, w, &a, &b);
 	ad = _PyLong_AsScaledDouble((PyObject *)a, &aexp);
@@ -2724,10 +2731,6 @@
 	Py_DECREF(b);
 	if (failed)
 		return NULL;
-	/* 'aexp' and 'bexp' were initialized to -1 to silence gcc-4.0.x,
-	   but should really be set correctly after sucessful calls to
-	   _PyLong_AsScaledDouble() */
-	assert(aexp >= 0 && bexp >= 0);
 
 	if (bd == 0.0) {
 		PyErr_SetString(PyExc_ZeroDivisionError,
@@ -2735,15 +2738,11 @@
 		return NULL;
 	}
 
-	/* True value is very close to ad/bd * 2**(PyLong_SHIFT*(aexp-bexp)) */
+	/* True value is very close to ad/bd * 2**(aexp-bexp) */
 	ad /= bd;	/* overflow/underflow impossible here */
-	aexp -= bexp;
-	if (aexp > INT_MAX / PyLong_SHIFT)
-		goto overflow;
-	else if (aexp < -(INT_MAX / PyLong_SHIFT))
-		return PyFloat_FromDouble(0.0);	/* underflow to 0 */
+	exp = (int)aexp - bexp;
 	errno = 0;
-	ad = ldexp(ad, aexp * PyLong_SHIFT);
+	ad = ldexp(ad, exp);
 	if (Py_OVERFLOWED(ad)) /* ignore underflow to 0.0 */
 		goto overflow;
 	return PyFloat_FromDouble(ad);
Index: Modules/mathmodule.c
===================================================================
--- Modules/mathmodule.c	(révision 70631)
+++ Modules/mathmodule.c	(copie de travail)
@@ -783,18 +783,18 @@
 	/* If it is long, do it ourselves. */
 	if (PyLong_Check(arg)) {
 		double x;
-		int e;
+		unsigned int e;
 		x = _PyLong_AsScaledDouble(arg, &e);
+		if (x == -1.0 && PyErr_Occurred())
+			return NULL;
 		if (x <= 0.0) {
 			PyErr_SetString(PyExc_ValueError,
 					"math domain error");
 			return NULL;
 		}
-		/* Value is ~= x * 2**(e*PyLong_SHIFT), so the log ~=
-		   log(x) + log(2) * e * PyLong_SHIFT.
-		   CAUTION:  e*PyLong_SHIFT may overflow using int arithmetic,
-		   so force use of double. */
-		x = func(x) + (e * (double)PyLong_SHIFT) * func(2.0);
+		/* Value is ~= x * 2**e,
+		 * so the log ~= log(x) + log(2) * e */
+		x = func(x) + e * func(2.0);
 		return PyFloat_FromDouble(x);
 	}