bpo-24658: Fix read/write greater than 2 GiB on macOS (GH-1705)
On macOS, fix reading from and writing into a file with a size larger than 2 GiB.
(cherry picked from commit 74a8b6ea7e0a8508b13a1c75ec9b91febd8b5557)
Co-authored-by: Stéphane Wirtel <stephane@wirtel.be>
diff --git a/Lib/test/test_largefile.py b/Lib/test/test_largefile.py
index 21296cc..8870c72 100644
--- a/Lib/test/test_largefile.py
+++ b/Lib/test/test_largefile.py
@@ -5,12 +5,12 @@
import stat
import sys
import unittest
-from test.support import TESTFN, requires, unlink
+from test.support import TESTFN, requires, unlink, bigmemtest
import io # C implementation of io
import _pyio as pyio # Python implementation of io
# size of file to create (>2 GiB; 2 GiB == 2,147,483,648 bytes)
-size = 2500000000
+size = 2_500_000_000
class LargeFileTest:
"""Test that each file function works as expected for large
@@ -45,6 +45,15 @@
raise cls.failureException('File was not truncated by opening '
'with mode "wb"')
+ # _pyio.FileIO.readall() uses a temporary bytearray then casted to bytes,
+ # so memuse=2 is needed
+ @bigmemtest(size=size, memuse=2, dry_run=False)
+ def test_large_read(self, _size):
+ # bpo-24658: Test that a read greater than 2GB does not fail.
+ with self.open(TESTFN, "rb") as f:
+ self.assertEqual(len(f.read()), size + 1)
+ self.assertEqual(f.tell(), size + 1)
+
def test_osstat(self):
self.assertEqual(os.stat(TESTFN)[stat.ST_SIZE], size+1)