Fix another tokenizer issue

parso/python/tokenize.py

@@ -457,10 +457,11 @@ def tokenize_lines(lines, version_info, start_pos=(1, 0)):
             pseudomatch = pseudo_token.match(line, pos)
             if not pseudomatch:                             # scan for tokens
                 match = whitespace.match(line, pos)
+                if pos == 0:
+                    for t in dedent_if_necessary(match.end()):
+                        yield t
                 pos = match.end()
                 new_line = False
-                for t in dedent_if_necessary(pos):
-                    yield t
                 yield PythonToken(
                     ERRORTOKEN, line[pos], (lnum, pos),
                     additional_prefix + match.group(0)

test/test_diff_parser.py

@@ -961,4 +961,8 @@ def test_random_unicode_characters(differ):
     differ.parse('\r\r', parsers=1)
     differ.parse("˟Ę\x05À\r   rúƣ@\x8a\x15r()\n", parsers=1, expect_error_leaves=True)
     differ.parse('a\ntaǁ\rGĒōns__\n\nb', parsers=1)
+    s = '        if not (self, "_fi\x02\x0e\x08\n\nle"):'
+    differ.parse(s, parsers=1, expect_error_leaves=True)
+    differ.parse('')
+    differ.parse(s + '\n', parsers=1, expect_error_leaves=True)
     differ.parse('')