bug#34525: replace-regexp missing some matches

[Alan Mackenzie <acm@muc.de>]

Hello, Stefan.

On Tue, Feb 26, 2019 at 15:09:54 -0500, Stefan Monnier wrote:
> > gl_state contains a cached interval, gl_state->backward_i, and there
> > is no guarantee that its ->position will have been updated by
> > adjust_intervals_for_insertion.  In the current bug, I believe it
> > hasn't been adjusted.

> Hmm... gl_state is not supposed to be kept "live" across buffer
> modifications.  It's supposed to be used only *within* read-only
> primitives which set it from scratch at the beginning (by calling
> SETUP_SYNTAX_TABLE, SETUP_BUFFER_SYNTAX_TABLE, or
> SETUP_SYNTAX_TABLE_FOR_OBJECT).  The backward_i and forward_i fields are
> actually reset in the first call to update_syntax_table, by passing it
> a true value for the `init` arg.

> So the problem you describe might be due to some place where we fail to
> reset gl_state before using it, or maybe it's a bug in
> SETUP_*_SYNTAX_TABLE*

re_search_2 calls SETUP_SYNTAX_TABLE_FOR_OBJECT unconditionally near its
start.  S_S_T_F_O calls update_syntax_table with a non-zero `init'
conditioned only on parse_sexp_lookup_properties.  This initialises
gl_state.backward_i and gl_state.forward_i.

So, I agree with you, what I am seeing is impossible.  I'm seeing it,
though.

>         Stefan

-- 
Alan Mackenzie (Nuremberg, Germany).