linux, cmdline(), fix for #1179, comment 552984549: sometimes string …

…ends with null byte but args are separated by spaces

psutil/_pslinux.py

@@ -1649,7 +1649,14 @@ def cmdline(self):
         sep = '\x00' if data.endswith('\x00') else ' '
         if data.endswith(sep):
             data = data[:-1]
-        return data.split(sep)
+        cmdline = data.split(sep)
+        # Sometimes last char is a null byte '\0' but the args are
+        # separated by spaces, see:
+        # https://github.com/giampaolo/psutil/
+        #     issues/1179#issuecomment-552984549
+        if sep == '\x00' and len(cmdline) == 1 and ' ' in data:
+            cmdline = data.split(' ')
+        return cmdline
 
     @wrap_exceptions
     def environ(self):

psutil/tests/test_linux.py

@@ -1837,6 +1837,14 @@ def test_cmdline_spaces_mocked(self):
             self.assertEqual(p.cmdline(), ['foo', 'bar', ''])
             assert m.called
 
+    def test_cmdline_mixed_separators(self):
+        p = psutil.Process()
+        fake_file = io.StringIO(u('foo\x20bar\x00'))
+        with mock.patch('psutil._common.open',
+                        return_value=fake_file, create=True) as m:
+            self.assertEqual(p.cmdline(), ['foo', 'bar'])
+            assert m.called
+
     def test_readlink_path_deleted_mocked(self):
         with mock.patch('psutil._pslinux.os.readlink',
                         return_value='/home/foo (deleted)'):