Merged revisions 68835 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk
........
r68835 | antoine.pitrou | 2009-01-21 01:45:36 +0100 (mer., 21 janv. 2009) | 6 lines
Issue #5008: When a file is opened in append mode with the new IO library,
do an explicit seek to the end of file (so that e.g. tell() returns the
file size rather than 0). This is consistent with the behaviour of the
traditional 2.x file object.
........
diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index 489e560..6265258 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -233,6 +233,17 @@
else:
self.fail("1/0 didn't raise an exception")
+ # issue 5008
+ def test_append_mode_tell(self):
+ with io.open(support.TESTFN, "wb") as f:
+ f.write(b"xxx")
+ with io.open(support.TESTFN, "ab", buffering=0) as f:
+ self.assertEqual(f.tell(), 3)
+ with io.open(support.TESTFN, "ab") as f:
+ self.assertEqual(f.tell(), 3)
+ with io.open(support.TESTFN, "a") as f:
+ self.assert_(f.tell() > 0)
+
def test_destructor(self):
record = []
class MyFileIO(io.FileIO):
diff --git a/Misc/NEWS b/Misc/NEWS
index 35506cb..b92048c 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -137,6 +137,11 @@
Library
-------
+- Issue #5008: When a file is opened in append mode with the new IO library,
+ do an explicit seek to the end of file (so that e.g. tell() returns the
+ file size rather than 0). This is consistent with the behaviour of the
+ traditional 2.x file object.
+
- Issue #5013: Fixed a bug in FileHandler which occurred when the delay
parameter was set.
diff --git a/Modules/_fileio.c b/Modules/_fileio.c
index 5b840c0..7a71837 100644
--- a/Modules/_fileio.c
+++ b/Modules/_fileio.c
@@ -55,6 +55,9 @@
#define PyFileIO_Check(op) (PyObject_TypeCheck((op), &PyFileIO_Type))
+static PyObject *
+portable_lseek(int fd, PyObject *posobj, int whence);
+
/* Returns 0 on success, -1 with exception set on failure. */
static int
internal_close(PyFileIOObject *self)
@@ -315,6 +318,16 @@
goto error;
}
+ if (append) {
+ /* For consistent behaviour, we explicitly seek to the
+ end of file (otherwise, it might be done only on the
+ first write()). */
+ PyObject *pos = portable_lseek(self->fd, NULL, 2);
+ if (pos == NULL)
+ goto error;
+ Py_DECREF(pos);
+ }
+
goto done;
error: