[Python-checkins] cpython (merge 3.2 -> default): Issue #11235: Fix OverflowError when trying to import a source file whose

[antoine.pitrou]

http://hg.python.org/cpython/rev/cb13d8cff050
changeset:   74597:cb13d8cff050
parent:      74595:75a3d35309cf
parent:      74596:a2f3d6986bfa
user:        Antoine Pitrou <solipsis at pitrou.net>
date:        Tue Jan 24 17:45:50 2012 +0100
summary:
  Issue #11235: Fix OverflowError when trying to import a source file whose modification time doesn't fit in a 32-bit timestamp.

files:
  Lib/importlib/test/source/test_file_loader.py |  17 ++++++++++
  Lib/test/test_import.py                       |  12 +++++++
  Misc/NEWS                                     |   3 +
  Python/import.c                               |  11 ++----
  4 files changed, 36 insertions(+), 7 deletions(-)


diff --git a/Lib/importlib/test/source/test_file_loader.py b/Lib/importlib/test/source/test_file_loader.py
--- a/Lib/importlib/test/source/test_file_loader.py
+++ b/Lib/importlib/test/source/test_file_loader.py
@@ -123,6 +123,23 @@
             pycache = os.path.dirname(imp.cache_from_source(file_path))
             shutil.rmtree(pycache)
 
+    def test_timestamp_overflow(self):
+        # When a modification timestamp is larger than 2**32, it should be
+        # truncated rather than raise an OverflowError.
+        with source_util.create_modules('_temp') as mapping:
+            source = mapping['_temp']
+            compiled = imp.cache_from_source(source)
+            with open(source, 'w') as f:
+                f.write("x = 5")
+            os.utime(source, (2 ** 33, 2 ** 33))
+            loader = _bootstrap._SourceFileLoader('_temp', mapping['_temp'])
+            mod = loader.load_module('_temp')
+            # Sanity checks.
+            self.assertEqual(mod.__cached__, compiled)
+            self.assertEqual(mod.x, 5)
+            # The pyc file was created.
+            os.stat(compiled)
+
 
 class BadBytecodeTest(unittest.TestCase):
 
diff --git a/Lib/test/test_import.py b/Lib/test/test_import.py
--- a/Lib/test/test_import.py
+++ b/Lib/test/test_import.py
@@ -306,6 +306,18 @@
             """))
         script_helper.assert_python_ok(testfn)
 
+    def test_timestamp_overflow(self):
+        # A modification timestamp larger than 2**32 should not be a problem
+        # when importing a module (issue #11235).
+        source = TESTFN + ".py"
+        compiled = imp.cache_from_source(source)
+        with open(source, 'w') as f:
+            pass
+        os.utime(source, (2 ** 33, 2 ** 33))
+        __import__(TESTFN)
+        # The pyc file was created.
+        os.stat(compiled)
+
 
 class PycRewritingTests(unittest.TestCase):
     # Test that the `co_filename` attribute on code objects always points
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,9 @@
 Core and Builtins
 -----------------
 
+- Issue #11235: Fix OverflowError when trying to import a source file whose
+  modification time doesn't fit in a 32-bit timestamp.
+
 - Issue #12705: A SyntaxError exception is now raised when attempting to
   compile multiple statements as a single interactive statement.
 
diff --git a/Python/import.c b/Python/import.c
--- a/Python/import.c
+++ b/Python/import.c
@@ -1478,14 +1478,11 @@
     }
 #if SIZEOF_TIME_T > 4
     /* Python's .pyc timestamp handling presumes that the timestamp fits
-       in 4 bytes. This will be fine until sometime in the year 2038,
-       when a 4-byte signed time_t will overflow.
+       in 4 bytes. Since the code only does an equality comparison,
+       ordering is not important and we can safely ignore the higher bits
+       (collisions are extremely unlikely).
      */
-    if (st.st_mtime >> 32) {
-        PyErr_SetString(PyExc_OverflowError,
-            "modification time overflows a 4 byte field");
-        goto error;
-    }
+    st.st_mtime &= 0xFFFFFFFF;
 #endif
     if (PyUnicode_READY(pathname) < 0)
         return NULL;

-- 
Repository URL: http://hg.python.org/cpython