Raise InvalidOperation if exponents of zeros are clamped during exact

conversion in the Decimal constructor. Exact here refers to the
representation and not to the value (clamping does not change the value).

diff --git a/Lib/test/test_decimal.py b/Lib/test/test_decimal.py
index 694b959e21870bebe330bc6200d6e4c27c08a29d..90f40155498168b7d5e1ef45f3d499af6b11354a 100644 (file)
--- a/Lib/test/test_decimal.py
+++ b/Lib/test/test_decimal.py
@@ -4953,6 +4953,30 @@ class CWhitebox(unittest.TestCase):
         self.assertRaises(ValueError, get_fmt, 12345, invalid_dot, 'g')
         self.assertRaises(ValueError, get_fmt, 12345, invalid_sep, 'g')
 
+    def test_exact_conversion(self):
+        Decimal = C.Decimal
+        localcontext = C.localcontext
+        InvalidOperation = C.InvalidOperation
+
+        with localcontext() as c:
+
+            c.traps[InvalidOperation] = True
+
+            # Clamped
+            x = "0e%d" % sys.maxsize
+            self.assertRaises(InvalidOperation, Decimal, x)
+
+            x = "0e%d" % (-sys.maxsize-1)
+            self.assertRaises(InvalidOperation, Decimal, x)
+
+            # Overflow
+            x = "1e%d" % sys.maxsize
+            self.assertRaises(InvalidOperation, Decimal, x)
+
+            # Underflow
+            x = "1e%d" % (-sys.maxsize-1)
+            self.assertRaises(InvalidOperation, Decimal, x)
+
 
 all_tests = [
   CExplicitConstructionTest, PyExplicitConstructionTest,

diff --git a/Modules/_decimal/_decimal.c b/Modules/_decimal/_decimal.c
index 32e336b4fff36d75635a22b4221d2890ac5691d3..ad3c3df3184c15f55a464e368f304e5d74222c24 100644 (file)
--- a/Modules/_decimal/_decimal.c
+++ b/Modules/_decimal/_decimal.c
@@ -1935,7 +1935,7 @@ PyDecType_FromCStringExact(PyTypeObject *type, const char *s,
     mpd_maxcontext(&maxctx);
 
     mpd_qset_string(MPD(dec), s, &maxctx, &status);
-    if (status & (MPD_Inexact|MPD_Rounded)) {
+    if (status & (MPD_Inexact|MPD_Rounded|MPD_Clamped)) {
         /* we want exact results */
         mpd_seterror(MPD(dec), MPD_Invalid_operation, &status);
     }
@@ -2139,7 +2139,7 @@ PyDecType_FromLongExact(PyTypeObject *type, const PyObject *pylong,
         return NULL;
     }
 
-    if (status & (MPD_Inexact|MPD_Rounded)) {
+    if (status & (MPD_Inexact|MPD_Rounded|MPD_Clamped)) {
         /* we want exact results */
         mpd_seterror(MPD(dec), MPD_Invalid_operation, &status);
     }

diff --git a/Modules/_decimal/tests/deccheck.py b/Modules/_decimal/tests/deccheck.py
index aefbed67af4671c88aea5e2e5ed18c8e67b61365..c8da4d02b737c1eaf7f3f2285599c8a70d86389e 100644 (file)
--- a/Modules/_decimal/tests/deccheck.py
+++ b/Modules/_decimal/tests/deccheck.py
@@ -302,6 +302,7 @@ def RestrictedDecimal(value):
     dec = maxcontext.create_decimal(value)
     if maxcontext.flags[P.Inexact] or \
        maxcontext.flags[P.Rounded] or \
+       maxcontext.flags[P.Clamped] or \
        maxcontext.flags[P.InvalidOperation]:
         return context.p._raise_error(P.InvalidOperation)
     if maxcontext.flags[P.FloatOperation]: