Fix also gzip.compress().

Author: serhiy-storchaka

Lib/gzip.py

@@ -668,6 +668,8 @@ def compress(data, compresslevel=_COMPRESS_LEVEL_TRADEOFF, *, mtime=0):
     gzip_data = zlib.compress(data, level=compresslevel, wbits=31)
     if mtime is None:
         mtime = time.time()
+    if not 0 <= mtime < 2**32:
+        mtime = 0
     # Reuse gzip header created by zlib, replace mtime and OS byte for
     # consistency.
     header = struct.pack("<4sLBB", gzip_data, int(mtime), gzip_data[8], 255)

Lib/test/test_gzip.py

@@ -356,15 +356,19 @@ def test_mtime_out_of_range(self):
             with gzip.GzipFile(self.filename, 'w', mtime=mtime) as fWrite:
                 fWrite.write(data1)
             with gzip.GzipFile(self.filename) as fRead:
-                fRead.read()
+                fRead.read(1)
+                self.assertEqual(fRead.mtime, 0)
+            datac = gzip.compress(data1, mtime=mtime)
+            with gzip.GzipFile(fileobj=io.BytesIO(datac)) as fRead:
+                fRead.read(1)
                 self.assertEqual(fRead.mtime, 0)
 
         for mtime in (-1, 2**32):
             with mock.patch('time.time', return_value=float(mtime)):
                 with gzip.GzipFile(self.filename, 'w') as fWrite:
                     fWrite.write(data1)
                 with gzip.GzipFile(self.filename) as fRead:
-                    fRead.read()
+                    fRead.read(1)
                     self.assertEqual(fRead.mtime, 0)
 
     def test_metadata(self):