From 4e10ed3b86cf08211ef0c9c5408799195c2c1881 Mon Sep 17 00:00:00 2001 From: Andrew MacIntyre Date: Sun, 4 Apr 2004 07:01:35 +0000 Subject: If a file is opened with an explicit buffer size >= 1, repeated close() calls would attempt to free() the buffer already free()ed on the first close(). [bug introduced with patch #788249] Making sure that the buffer is free()ed in file object deallocation is a belt-n-braces bit of insurance against a memory leak. --- Lib/test/test_file.py | 17 +++++++++++++++++ Misc/NEWS | 4 ++++ Objects/fileobject.c | 2 ++ 3 files changed, 23 insertions(+) diff --git a/Lib/test/test_file.py b/Lib/test/test_file.py index b8bcab7..22db9a2 100644 --- a/Lib/test/test_file.py +++ b/Lib/test/test_file.py @@ -109,6 +109,23 @@ f.close() if not f.closed: raise TestFailed, 'file.closed should be true' +# make sure that explicitly setting the buffer size doesn't cause +# misbehaviour especially with repeated close() calls +for s in (-1, 0, 1, 512): + try: + f = open(TESTFN, 'w', s) + f.write(str(s)) + f.close() + f.close() + f = open(TESTFN, 'r', s) + d = int(f.read()) + f.close() + f.close() + except IOError, msg: + raise TestFailed, 'error setting buffer size %d: %s' % (s, str(msg)) + if d != s: + raise TestFailed, 'readback failure using buffer size %d' + methods = ['fileno', 'flush', 'isatty', 'next', 'read', 'readinto', 'readline', 'readlines', 'seek', 'tell', 'truncate', 'write', 'xreadlines', '__iter__'] diff --git a/Misc/NEWS b/Misc/NEWS index 9fc3ba7..b1f2043 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -194,6 +194,10 @@ Core and builtins the data and the data length. Instead, the appropriate tp_as_buffer method is called as necessary. +- fixed: if a file is opened with an explicit buffer size >= 1, repeated + close() calls would attempt to free() the buffer already free()ed on + the first call. + Extension modules ----------------- diff --git a/Objects/fileobject.c b/Objects/fileobject.c index c973366..6b7e01b 100644 --- a/Objects/fileobject.c +++ b/Objects/fileobject.c @@ -312,6 +312,7 @@ file_dealloc(PyFileObject *f) (*f->f_close)(f->f_fp); Py_END_ALLOW_THREADS } + PyMem_Free(f->f_setbuf); Py_XDECREF(f->f_name); Py_XDECREF(f->f_mode); Py_XDECREF(f->f_encoding); @@ -358,6 +359,7 @@ file_close(PyFileObject *f) f->f_fp = NULL; } PyMem_Free(f->f_setbuf); + f->f_setbuf = NULL; if (sts == EOF) return PyErr_SetFromErrno(PyExc_IOError); if (sts != 0) -- cgit v0.12