Hi Peff,

On Thu, 29 Mar 2018, Jeff King wrote:

On Thu, Mar 29, 2018 at 05:19:00PM +0200, Johannes Schindelin wrote:

quoted

Let's generalize this observation to this conservative strategy: if we
are removing the last entry from a section, and there are no comments
inside that section nor surrounding it, then remove the entire section.
Otherwise behave as before: leave the now-empty section (including those
comments, even the one about the now-deleted entry).

Yep, as I said earlier, this makes a ton of sense to me.

[... thorough review ...]

Thank you for taking the time (and figuring out my off-by-ones, am I not
the king of those?).

Your in-depth analysis of the backtracking approach also makes sense, in
particular the awful bug that looks very, very similar to what 1/9 fixes
elsewhere.

I'll take some time to go over your comments in detail, but there is one
suggestion that I think I'll want to pursue first:

I guess the holy grail would be a parser which reports _all_ syntactic
events (section names, keys, comments, whitespace, etc) as a stream
without storing anything. And then the normal reader could just discard
the non-key events, and the writer here could build the tree from those
events.

I already changed the do_config_from_file()/do_config_from() code path to
allow for handing back section headers. And I *think* that approach should
be easily extended to allow for an optional callback for these syntactic
events (and we do not need more than that, as the parsed "tree" really is
a list: there is nothing nested about ini files, so we really only have a
linear list of blocks (event type, offset range)).

I'll think about this a little bit, and hopefully come back with v2 in a
while that uses that approach.

Thank you so much for that suggestion,
Dscho