diff --git a/Lib/test/test_mmap.py b/Lib/test/test_mmap.py index 31b369517c5..0701b9621d8 100644 --- a/Lib/test/test_mmap.py +++ b/Lib/test/test_mmap.py @@ -469,18 +469,15 @@ class MmapTests(unittest.TestCase): def test_empty_file (self): f = open (TESTFN, 'w+b') f.close() - f = open(TESTFN, "rb") - try: - m = mmap.mmap(f.fileno(), 0, access=mmap.ACCESS_READ) - m.close() - f.close() - self.fail("should not have been able to mmap empty file") - except ValueError as e: - f.close() - self.assertEqual(e.message, "cannot mmap an empty file") - except: - f.close() - self.fail("unexpected exception: " + str(e)) + with open(TESTFN, "rb") as f : + try: + m = mmap.mmap(f.fileno(), 0, access=mmap.ACCESS_READ) + m.close() + self.fail("should not have been able to mmap empty file") + except ValueError as e: + self.assertEqual(e.message, "cannot mmap an empty file") + except: + self.fail("unexpected exception: " + str(e)) def test_offset (self): f = open (TESTFN, 'w+b') diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c index 8cf0e8743fe..62d934c607f 100644 --- a/Modules/mmapmodule.c +++ b/Modules/mmapmodule.c @@ -1388,6 +1388,11 @@ new_mmap_object(PyTypeObject *type, PyObject *args, PyObject *kwdict) } size = (((PY_LONG_LONG) high) << 32) + low; + if (size == 0) { + PyErr_SetString(PyExc_ValueError, + "cannot mmap an empty file"); + return NULL; + } if (offset >= size) { PyErr_SetString(PyExc_ValueError, "mmap offset is greater than file size");