Fix an issue with unfinished f string literals

parso/python/tokenize.py

@@ -649,6 +649,17 @@ def tokenize_lines(lines, version_info, start_pos=(1, 0)):
         if contstr.endswith('\n') or contstr.endswith('\r'):
             new_line = True
 
+    if fstring_stack:
+        tos = fstring_stack[-1]
+        if tos.previous_lines:
+            yield PythonToken(
+                FSTRING_STRING, tos.previous_lines,
+                tos.last_string_start_pos,
+                # Never has a prefix because it can start anywhere and
+                # include whitespace.
+                prefix=''
+            )
+
     end_pos = lnum, max
     # As the last position we just take the maximally possible position. We
     # remove -1 for the last new line.

test/test_get_code.py

@@ -118,3 +118,16 @@ def test_carriage_return_at_end(code, types):
     assert tree.get_code() == code
     assert [c.type for c in tree.children] == types
     assert tree.end_pos == (len(code) + 1, 0)
+
+
+@pytest.mark.parametrize('code', [
+    ' ',
+    '    F"""',
+    '    F"""\n',
+    '    F""" \n',
+    '    F""" \n3',
+    '    f"""\n"""',
+    '    f"""\n"""\n',
+])
+def test_full_code_round_trip(code):
+    assert parse(code).get_code() == code