Re: [COMMITTERS] pgsql: Retain comments on indexes and constraints at ALTER TABLE ... TY

Heikki Linnakangas wrote:
> On 07/17/2015 05:40 PM, Michael Paquier wrote:
> >On Fri, Jul 17, 2015 at 11:16 PM, Kevin Grittner <kgrittn@ymail.com> wrote:
> >>Heikki Linnakangas <heikki.linnakangas@iki.fi> wrote:
> >>
> >>>This fixes bug #13126, reported by Kirill Simonov.
> >>
> >>It looks like you missed something with the addition of
> >>AT_ReAddComment:
> >>
> >>test_ddl_deparse.c:80:11: warning: enumeration value 'AT_ReAddComment' not handled in switch [-Wswitch]
> >>                 switch (subcmd->subtype)
> >>                         ^
> >
> >Oops. If someone could pick up the attached (backpatch to 9.5 needed)...
> 
> Hmm, that function is pretty fragile, it will segfault on any AT_* type that
> it doesn't recognize. Thankfully you get that compiler warning, but we have
> added AT_* type codes before in minor releases.

Yeah, that module was put together in a bit of a rush when I decided to
remove the JSON deparsing part of the DDL patch.

> I couldn't quite figure out what the purpose of that module is, as
> there is no documentation or README or file-header comments on it.

Well, since it's in src/test/modules I thought it was clear that the
intention is just to be able to test the pg_ddl_command type --
obviously not.  I will add a README or something.

> If it's there just to so you can run the regression tests that come
> with it, it might make sense to just add a "default" case to that
> switch to handle any unrecognized commands, and perhaps even remove
> the cases for the currently untested subcommands as it's just dead
> code.

Well, I would prefer to have an output that says "unrecognized" and then
add more test cases to the SQL files so that there's not so much dead
code.  I prefer that to removing the C support code, because then as
we add extra tests we don't need to modify the C source.

> If it's supposed to act like a sample that you can copy-paste and
> modify, then perhaps that would still be the best option, and add a
> comment there explaining that it only cares about the most common
> subtypes but you can add handlers for others if necessary.

I wasn't thinking in having it be useful for copy-paste.  My longer-term
plan is to have the JSON deparsing extension live in src/extensions.

-- 
Álvaro Herrera                http://www.2ndQuadrant.com/
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