[Python-checkins] r68837 - in python/branches/release26-maint: Lib/test/test_io.py Misc/NEWS Modules/_fileio.c

[antoine.pitrou]

Author: antoine.pitrou
Date: Wed Jan 21 01:56:37 2009
New Revision: 68837

Log:
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.
........


Modified:
   python/branches/release26-maint/   (props changed)
   python/branches/release26-maint/Lib/test/test_io.py
   python/branches/release26-maint/Misc/NEWS
   python/branches/release26-maint/Modules/_fileio.c

Modified: python/branches/release26-maint/Lib/test/test_io.py
==============================================================================
--- python/branches/release26-maint/Lib/test/test_io.py	(original)
+++ python/branches/release26-maint/Lib/test/test_io.py	Wed Jan 21 01:56:37 2009
@@ -232,6 +232,17 @@
             else:
                 self.fail("1/0 didn't raise an exception")
 
+    # issue 5008
+    def test_append_mode_tell(self):
+        with io.open(test_support.TESTFN, "wb") as f:
+            f.write(b"xxx")
+        with io.open(test_support.TESTFN, "ab", buffering=0) as f:
+            self.assertEqual(f.tell(), 3)
+        with io.open(test_support.TESTFN, "ab") as f:
+            self.assertEqual(f.tell(), 3)
+        with io.open(test_support.TESTFN, "a") as f:
+            self.assert_(f.tell() > 0)
+
     def test_destructor(self):
         record = []
         class MyFileIO(io.FileIO):

Modified: python/branches/release26-maint/Misc/NEWS
==============================================================================
--- python/branches/release26-maint/Misc/NEWS	(original)
+++ python/branches/release26-maint/Misc/NEWS	Wed Jan 21 01:56:37 2009
@@ -76,6 +76,11 @@
 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 #3997: zipfiles generated with more than 65536 files could not be
   opened with other applications.
 

Modified: python/branches/release26-maint/Modules/_fileio.c
==============================================================================
--- python/branches/release26-maint/Modules/_fileio.c	(original)
+++ python/branches/release26-maint/Modules/_fileio.c	Wed Jan 21 01:56:37 2009
@@ -41,6 +41,9 @@
 
 #define PyFileIO_Check(op) (PyObject_TypeCheck((op), &PyFileIO_Type))
 
+static PyObject *
+portable_lseek(int fd, PyObject *posobj, int whence);
+
 /* Returns 0 on success, errno (which is < 0) on failure. */
 static int
 internal_close(PyFileIOObject *self)
@@ -296,6 +299,16 @@
 			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: