Coverage is now '99%'. Unless I see problems that are more than trivial, I am going to polish the patch and commit.

I believe partial coverage of "for context in editwin.num_context_lines:" is because the iterable is never empty. But it never will be in practice and I believe the code is not intended to work if it is. So I ignore this.

I believe partial coverage of deeply nested 
                    if rawtext[pos] in "'\"": 
is because this is reached with rawtext[pop] *not* in "'\"". Reading up, to reach this point, rawtext[pos] must also not be in "([":,
   bracketing[brck_index][0] == brck_limit
must never become true inside the while look (because it breaks), and pos == brck_limit must be true. I don't know if this is all possible. Tal, if you find a triggering test case after I commit, it can be added later.