New issue:

find_good_parse_start() call in editor.py has the wrong signature.  There's actually a few things going on here.  Here's the section in editor:
```
            if not self.context_use_ps1:
                for context in self.num_context_lines:
                    startat = max(lno - context, 1)
                    startatindex = repr(startat) + ".0"
                    rawtext = text.get(startatindex, "insert")
                    y.set_code(rawtext)
                    bod = y.find_good_parse_start(
                              self.context_use_ps1, self._build_char_in_string_func(startatindex))
                    if bod is not None or startat == 1:
                        break
                y.set_lo(bod or 0)
            else:
                r = text.tag_prevrange("console", "insert")
                if r:
                    startatindex = r[1]
                else:
                    startatindex = "1.0"
                rawtext = text.get(startatindex, "insert")
                y.set_code(rawtext)
                y.set_lo(0)
```

1. self.context_use_ps1 is always False.  There's no where in IDLE that it can be set to True.  I'll open an another issue for this since it's really not pyparse.

2. The call to find_good_parse_start:
```
bod = y.find_good_parse_start(
                              self.context_use_ps1, self._build_char_in_string_func(startatindex))
```
sends 3 parameters.  And in pyparse, the signature allows 3.  However, the signature is:
```
    def find_good_parse_start(self, is_char_in_string=None,
                              _synchre=_synchre):
```

This means that the False self.use_context_ps1 is the first value instead of the function, so pyparse is always executing:
```
        if not is_char_in_string:
            # no clue -- make the caller pass everything
            return None
```
In the test, I had assumed this was for the default of None.  Bad assumption.  :-(

Here's the commit that changed the signature:
https://github.com/python/cpython/commit/b17544551fc8dfd1304d5679c6e444cad4d34d97