Merged revisions 87942 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/branches/py3k

........
  r87942 | alexander.belopolsky | 2011-01-11 16:44:00 -0500 (Tue, 11 Jan 2011) | 3 lines

  Issue #5109: array.array constructor will now use fast code when
  initial data is provided in an array object with correct type.
........

Lib/test/test_array.py

@@ -239,6 +239,11 @@ class BaseTest(unittest.TestCase):
         if a.itemsize>1:
             self.assertRaises(ValueError, b.fromstring, "x")
 
+    def test_fromarray(self):
+        a = array.array(self.typecode, self.example)
+        b = array.array(self.typecode, a)
+        self.assertEqual(a, b)
+
     def test_repr(self):
         a = array.array(self.typecode, 2*self.example)
         self.assertEqual(a, eval(repr(a), {"array": array.array}))
@@ -958,6 +963,11 @@ class NumberTest(BaseTest):
 
         self.assertRaises(AttributeError, setattr, a, "color", "blue")
 
+    def test_frombytearray(self):
+        a = array.array('b', range(10))
+        b = array.array(self.typecode, a)
+        self.assertEqual(a, b)
+
 class SignedNumberTest(NumberTest):
     example = [-1, 0, 1, 42, 0x7f]
     smallerexample = [-1, 0, 1, 42, 0x7e]

Misc/NEWS

@@ -973,6 +973,9 @@ Library
 Extension Modules
 -----------------
 
+- Issue #5109: array.array constructor will now use fast code when
+  initial data is provided in an array object with correct type.
+
 - Issue #7384: If the system readline library is linked against ncurses,
   the curses module must be linked against ncurses as well. Otherwise it
   is not safe to load both the readline and curses modules in an application.

Modules/arraymodule.c

@@ -1925,7 +1925,10 @@ array_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
 
     if (!(initial == NULL || PyList_Check(initial)
           || PyString_Check(initial) || PyTuple_Check(initial)
-          || (c == 'u' && PyUnicode_Check(initial)))) {
+          || PyTuple_Check(initial)
+          || ((c=='u') && PyUnicode_Check(initial))
+          || (array_Check(initial)
+              && c == ((arrayobject*)initial)->ob_descr->typecode))) {
         it = PyObject_GetIter(initial);
         if (it == NULL)
             return NULL;
@@ -1941,17 +1944,20 @@ array_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
             PyObject *a;
             Py_ssize_t len;
 
-            if (initial == NULL || !(PyList_Check(initial)
-                || PyTuple_Check(initial)))
+            if (initial == NULL)
                 len = 0;
+            else if (PyList_Check(initial))
+                len = PyList_GET_SIZE(initial);
+            else if (PyTuple_Check(initial) || array_Check(initial))
+                len = Py_SIZE(initial);
             else
-                len = PySequence_Size(initial);
+                len = 0;
 
             a = newarrayobject(type, len, descr);
             if (a == NULL)
                 return NULL;
 
-            if (len > 0) {
+            if (len > 0 && !array_Check(initial)) {
                 Py_ssize_t i;
                 for (i = 0; i < len; i++) {
                     PyObject *v =
@@ -2001,6 +2007,11 @@ array_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
                 }
 #endif
             }
+            else if (initial != NULL && array_Check(initial)) {
+                arrayobject *self = (arrayobject *)a;
+                arrayobject *other = (arrayobject *)initial;
+                memcpy(self->ob_item, other->ob_item, len * other->ob_descr->itemsize);
+            }
             if (it != NULL) {
                 if (array_iter_extend((arrayobject *)a, it) == -1) {
                     Py_DECREF(it);