python: Add test for issue29.

python/test/test_seq.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python
+# coding: utf-8
+
+from nose import main
+from nose.tools import *
+
+import StringIO
+import msgpack
+
+binarydata = [chr(i) for i in xrange(256)]
+binarydata = "".join(binarydata)
+
+def gen_binary_data(idx):
+    data = binarydata[:idx % 300]
+    return data
+
+def test_exceeding_unpacker_read_size():
+    dumpf = StringIO.StringIO()
+
+    packer = msgpack.Packer()
+
+    NUMBER_OF_STRINGS = 6
+    read_size = 16
+                                # 5 ok for read_size=16, while 6 glibc detected *** python: double free or corruption (fasttop):
+                                # 20 ok for read_size=256, while 25 segfaults / glibc detected *** python: double free or corruption (!prev)
+                                # 40 ok for read_size=1024, while 50 introduces errors
+                                # 7000 ok for read_size=1024*1024, while 8000 leads to  glibc detected *** python: double free or corruption (!prev):
+
+    for idx in xrange(NUMBER_OF_STRINGS):
+        data = gen_binary_data(idx)
+        dumpf.write(packer.pack(data))
+
+    f = StringIO.StringIO(dumpf.getvalue())
+    dumpf.close()
+
+    unpacker = msgpack.Unpacker(f, read_size=read_size)
+
+    read_count = 0
+    for idx, o in enumerate(unpacker):
+        assert_equal(type(o), str)
+        assert_equal(o, gen_binary_data(idx))
+        read_count += 1
+
+    assert_equal(read_count, NUMBER_OF_STRINGS)
+
+
+if __name__ == '__main__':
+    # main()
+    test_exceeding_unpacker_read_size()