diff options
| -rw-r--r-- | Lib/test/test_mmap.py | 16 | ||||
| -rw-r--r-- | Misc/NEWS | 3 | ||||
| -rw-r--r-- | Modules/mmapmodule.c | 5 |
3 files changed, 24 insertions, 0 deletions
diff --git a/Lib/test/test_mmap.py b/Lib/test/test_mmap.py index 2c2863e..31b3695 100644 --- a/Lib/test/test_mmap.py +++ b/Lib/test/test_mmap.py @@ -466,6 +466,22 @@ class MmapTests(unittest.TestCase): f.flush () return mmap.mmap (f.fileno(), 0) + 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)) + def test_offset (self): f = open (TESTFN, 'w+b') @@ -103,6 +103,9 @@ Core and Builtins Library ------- +- Issue #15676: Now "mmap" check for empty files before doing the + offset check. Patch by Steven Willis. + - Issue #15340: Fix importing the random module when /dev/urandom cannot be opened. This was a regression caused by the hash randomization patch. diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c index a5027f5..8cf0e87 100644 --- a/Modules/mmapmodule.c +++ b/Modules/mmapmodule.c @@ -1189,6 +1189,11 @@ new_mmap_object(PyTypeObject *type, PyObject *args, PyObject *kwdict) if (fd != -1 && fstat(fd, &st) == 0 && S_ISREG(st.st_mode)) { if (map_size == 0) { off_t calc_size; + if (st.st_size == 0) { + PyErr_SetString(PyExc_ValueError, + "cannot mmap an empty file"); + return NULL; + } if (offset >= st.st_size) { PyErr_SetString(PyExc_ValueError, "mmap offset is greater than file size"); |