[pypy-svn] pypy default: - Mark the undocumented bytes.__alloc__() as an implementation

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: 
Changeset: r41702:1b4cca12e352
Date: 2011-02-08 17:58 +0100
http://bitbucket.org/pypy/pypy/changeset/1b4cca12e352/

Log:	- Mark the undocumented bytes.__alloc__() as an implementation
	detail for now.

	- Test the different behavior we have w.r.t. taking a buffer() on
	a bytearray and mutating the bytearray at the same time.

diff --git a/lib-python/2.7.0/test/test_bytes.py b/lib-python/modified-2.7.0/test/test_bytes.py
copy from lib-python/2.7.0/test/test_bytes.py
copy to lib-python/modified-2.7.0/test/test_bytes.py
--- a/lib-python/2.7.0/test/test_bytes.py
+++ b/lib-python/modified-2.7.0/test/test_bytes.py
@@ -632,6 +632,7 @@
         self.assertEqual(b, b1)
         self.assertTrue(b is b1)
 
+    @test.test_support.impl_detail("undocumented bytes.__alloc__()")
     def test_alloc(self):
         b = bytearray()
         alloc = b.__alloc__()
@@ -759,6 +760,8 @@
         self.assertEqual(b, b"")
         self.assertEqual(c, b"")
 
+    @test.test_support.impl_detail(
+        "resizing semantics of CPython rely on refcounting")
     def test_resize_forbidden(self):
         # #4509: can't resize a bytearray when there are buffer exports, even
         # if it wouldn't reallocate the underlying buffer.
@@ -791,6 +794,26 @@
         self.assertRaises(BufferError, delslice)
         self.assertEquals(b, orig)
 
+    @test.test_support.impl_detail("resizing semantics", cpython=False)
+    def test_resize_forbidden_non_cpython(self):
+        # on non-CPython implementations, we cannot prevent changes to
+        # bytearrays just because there are buffers around.  Instead,
+        # we get (on PyPy) a buffer that follows the changes and resizes.
+        b = bytearray(range(10))
+        for v in [memoryview(b), buffer(b)]:
+            b[5] = 99
+            self.assertIn(v[5], (99, chr(99)))
+            b[5] = 100
+            b += b
+            b += b
+            b += b
+            self.assertEquals(len(v), 80)
+            self.assertIn(v[5], (100, chr(100)))
+            self.assertIn(v[79], (9, chr(9)))
+            del b[10:]
+            self.assertRaises(IndexError, lambda: v[10])
+            self.assertEquals(len(v), 10)
+
     def test_empty_bytearray(self):
         # Issue #7561: operations on empty bytearrays could crash in many
         # situations, due to a fragile implementation of the