Reset out-of-range mtime to 0 even if explicitly provided.

Author: serhiy-storchaka

Lib/gzip.py

@@ -206,9 +206,6 @@ def __init__(self, filename=None, mode=None,
         if mode and 'b' not in mode:
             mode += 'b'
 
-        if mtime is not None and (mtime < 0 or mtime >= 2**32):
-            raise ValueError(f'mtime must be in the range 0 through {2**32-1}')
-
         try:
             if fileobj is None:
                 fileobj = self.myfileobj = builtins.open(filename, mode or 'rb')
@@ -301,8 +298,8 @@ def _write_gzip_header(self, compresslevel):
         mtime = self._write_mtime
         if mtime is None:
             mtime = time.time()
-            if mtime < 0 or mtime >= 2**32:
-                mtime = 0
+        if not 0 <= mtime < 2**32:
+            mtime = 0
         write32u(self.fileobj, int(mtime))
         if compresslevel == _COMPRESS_LEVEL_BEST:
             xfl = b'\002'

Lib/test/test_gzip.py

@@ -352,17 +352,13 @@ def test_mtime(self):
             self.assertEqual(fRead.mtime, mtime)
 
     def test_mtime_out_of_range(self):
-        # ValueError should be raised when mtime<0 or mtime>=2**32 and is
-        # explicitly specified
-        with self.assertRaises(ValueError):
-            with gzip.GzipFile(self.filename, 'w', mtime=-1) as fWrite:
-                pass
-        with self.assertRaises(ValueError):
-            with gzip.GzipFile(self.filename, 'w', mtime=2**32) as fWrite:
-                pass
+        for mtime in (-1, 2**32):
+            with gzip.GzipFile(self.filename, 'w', mtime=mtime) as fWrite:
+                fWrite.write(data1)
+            with gzip.GzipFile(self.filename) as fRead:
+                fRead.read()
+                self.assertEqual(fRead.mtime, 0)
 
-        # mtime should be set to 0 when time.time() is out of range and mtime is
-        # not explicitly given
         for mtime in (-1, 2**32):
             with mock.patch('time.time', return_value=float(mtime)):
                 with gzip.GzipFile(self.filename, 'w') as fWrite: