[Python-checkins] r70353 - in python/branches/release30-maint: Lib/test/test_largefile.py Misc/NEWS Modules/_fileio.c

[antoine.pitrou]

Author: antoine.pitrou
Date: Sat Mar 14 00:46:17 2009
New Revision: 70353

Log:
Merged revisions 70352 via svnmerge from 
svn+ssh://pythondev@svn.python.org/python/branches/py3k

........
  r70352 | antoine.pitrou | 2009-03-14 00:42:55 +0100 (sam., 14 mars 2009) | 4 lines
  
  Issue #5016: FileIO.seekable() could return False if the file position
  was negative when truncated to a C int. Patch by Victor Stinner.
........


Modified:
   python/branches/release30-maint/   (props changed)
   python/branches/release30-maint/Lib/test/test_largefile.py
   python/branches/release30-maint/Misc/NEWS
   python/branches/release30-maint/Modules/_fileio.c

Modified: python/branches/release30-maint/Lib/test/test_largefile.py
==============================================================================
--- python/branches/release30-maint/Lib/test/test_largefile.py	(original)
+++ python/branches/release30-maint/Lib/test/test_largefile.py	Sat Mar 14 00:46:17 2009
@@ -131,6 +131,15 @@
             f.seek(0)
             self.assertEqual(len(f.read()), 1)  # else wasn't truncated
 
+    def test_seekable(self):
+        # Issue #5016; seekable() can return False when the current position
+        # is negative when truncated to an int.
+        for pos in (2**31-1, 2**31, 2**31+1):
+            with open(TESTFN, 'rb') as f:
+                f.seek(pos)
+                self.assert_(f.seekable())
+
+
 def test_main():
     # On Windows and Mac OSX this test comsumes large resources; It
     # takes a long time to build the >2GB file and takes >2GB of disk
@@ -165,6 +174,7 @@
     with open(TESTFN, 'w') as f:
         if hasattr(f, 'truncate'):
             suite.addTest(TestCase('test_truncate'))
+    suite.addTest(TestCase('test_seekable'))
     unlink(TESTFN)
     try:
         run_unittest(suite)

Modified: python/branches/release30-maint/Misc/NEWS
==============================================================================
--- python/branches/release30-maint/Misc/NEWS	(original)
+++ python/branches/release30-maint/Misc/NEWS	Sat Mar 14 00:46:17 2009
@@ -24,6 +24,9 @@
 Library
 -------
 
+- Issue #5016: FileIO.seekable() could return False if the file position
+  was negative when truncated to a C int. Patch by Victor Stinner.
+
 - Issue #5179: Fixed subprocess handle leak on failure on windows.
 
 - Issue #5282: Fixed mmap resize on 32bit windows and unix. When offset > 0,

Modified: python/branches/release30-maint/Modules/_fileio.c
==============================================================================
--- python/branches/release30-maint/Modules/_fileio.c	(original)
+++ python/branches/release30-maint/Modules/_fileio.c	Sat Mar 14 00:46:17 2009
@@ -58,6 +58,8 @@
 static PyObject *
 portable_lseek(int fd, PyObject *posobj, int whence);
 
+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)
@@ -396,14 +398,14 @@
 	if (self->fd < 0)
 		return err_closed();
 	if (self->seekable < 0) {
-		int ret;
-		Py_BEGIN_ALLOW_THREADS
-		ret = lseek(self->fd, 0, SEEK_CUR);
-		Py_END_ALLOW_THREADS
-		if (ret < 0)
+		PyObject *pos = portable_lseek(self->fd, NULL, SEEK_CUR);
+		if (pos == NULL) {
+			PyErr_Clear();
 			self->seekable = 0;
-		else
+		} else {
+			Py_DECREF(pos);
 			self->seekable = 1;
+		}
 	}
 	return PyBool_FromLong((long) self->seekable);
 }