bpo-34974: Do not replace unexpected errors in bytes() and bytearray(). (GH-9852)

serhiy-storchaka · web-flow · commit e890421e334c · 2018-10-15T00:02:57.000+03:00
bytes and bytearray constructors converted unexpected exceptions
(e.g. MemoryError and KeyboardInterrupt) to TypeError.
diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
@@ -126,8 +126,8 @@ def test_from_buffer(self):
         a = self.type2test(b"\x01\x02\x03")
         self.assertEqual(a, b"\x01\x02\x03")
 
-        # http://bugs.python.org/issue29159
-        # Fallback when __index__ raises exception other than OverflowError
+        # Issues #29159 and #34974.
+        # Fallback when __index__ raises a TypeError
         class B(bytes):
             def __index__(self):
                 raise TypeError
@@ -184,6 +184,20 @@ def test_constructor_overflow(self):
         except (OverflowError, MemoryError):
             pass
 
+    def test_constructor_exceptions(self):
+        # Issue #34974: bytes and bytearray constructors replace unexpected
+        # exceptions.
+        class BadInt:
+            def __index__(self):
+                1/0
+        self.assertRaises(ZeroDivisionError, self.type2test, BadInt())
+        self.assertRaises(ZeroDivisionError, self.type2test, [BadInt()])
+
+        class BadIterable:
+            def __iter__(self):
+                1/0
+        self.assertRaises(ZeroDivisionError, self.type2test, BadIterable())
+
     def test_compare(self):
         b1 = self.type2test([1, 2, 3])
         b2 = self.type2test([1, 2, 3])
diff --git a/Misc/NEWS.d/next/Core and Builtins/2018-10-13-22-24-19.bpo-34974.7LgTc2.rst b/Misc/NEWS.d/next/Core and Builtins/2018-10-13-22-24-19.bpo-34974.7LgTc2.rst
@@ -0,0 +1,3 @@
+:class:`bytes` and :class:`bytearray` constructors no longer convert
+unexpected exceptions (e.g. :exc:`MemoryError` and :exc:`KeyboardInterrupt`)
+to :exc:`TypeError`.
diff --git a/Objects/bytearrayobject.c b/Objects/bytearrayobject.c
@@ -41,7 +41,6 @@ _getbytevalue(PyObject* arg, int *value)
     } else {
         PyObject *index = PyNumber_Index(arg);
         if (index == NULL) {
-            PyErr_Format(PyExc_TypeError, "an integer is required");
             *value = -1;
             return 0;
         }
@@ -821,7 +820,7 @@ bytearray_init(PyByteArrayObject *self, PyObject *args, PyObject *kwds)
     if (PyIndex_Check(arg)) {
         count = PyNumber_AsSsize_t(arg, PyExc_OverflowError);
         if (count == -1 && PyErr_Occurred()) {
-            if (PyErr_ExceptionMatches(PyExc_OverflowError))
+            if (!PyErr_ExceptionMatches(PyExc_TypeError))
                 return -1;
             PyErr_Clear();  /* fall through */
         }
diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
@@ -2596,7 +2596,7 @@ bytes_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
     if (PyIndex_Check(x)) {
         size = PyNumber_AsSsize_t(x, PyExc_OverflowError);
         if (size == -1 && PyErr_Occurred()) {
-            if (PyErr_ExceptionMatches(PyExc_OverflowError))
+            if (!PyErr_ExceptionMatches(PyExc_TypeError))
                 return NULL;
             PyErr_Clear();  /* fall through */
         }
@@ -2778,6 +2778,9 @@ PyBytes_FromObject(PyObject *x)
             Py_DECREF(it);
             return result;
         }
+        if (!PyErr_ExceptionMatches(PyExc_TypeError)) {
+            return NULL;
+        }
     }
 
     PyErr_Format(PyExc_TypeError,

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	+:class:`bytes` and :class:`bytearray` constructors no longer convert
	`2`	+unexpected exceptions (e.g. :exc:`MemoryError` and :exc:`KeyboardInterrupt`)
	`3`	+to :exc:`TypeError`.
Original file line number	Diff line number	Diff line change
`@@ -2596,7 +2596,7 @@ bytes_new(PyTypeObject type, PyObject args, PyObject *kwds)`
`2596`	`2596`	`if (PyIndex_Check(x)) {`
`2597`	`2597`	`size = PyNumber_AsSsize_t(x, PyExc_OverflowError);`
`2598`	`2598`	`if (size == -1 && PyErr_Occurred()) {`
`2599`		`- if (PyErr_ExceptionMatches(PyExc_OverflowError))`
	`2599`	`+ if (!PyErr_ExceptionMatches(PyExc_TypeError))`
`2600`	`2600`	`return NULL;`
`2601`	`2601`	`PyErr_Clear(); /* fall through */`
`2602`	`2602`	`}`
`@@ -2778,6 +2778,9 @@ PyBytes_FromObject(PyObject *x)`
`2778`	`2778`	`Py_DECREF(it);`
`2779`	`2779`	`return result;`
`2780`	`2780`	`}`
	`2781`	`+ if (!PyErr_ExceptionMatches(PyExc_TypeError)) {`
	`2782`	`+ return NULL;`
	`2783`	`+ }`
`2781`	`2784`	`}`
`2782`	`2785`
`2783`	`2786`	`PyErr_Format(PyExc_TypeError,`