Re: pg_plan_advice

> Thanks. The changes to the Makefile seem to mirror what is done in
> contrib/isn/Makefile, but I'm not so sure about the meson.build
> changes. sepgsql uses dir_data / 'contrib' rather than
> dir_include_server. src/pl/pl{perl,pgsql,python} use
> dir_include_server, but they also live in src/pl, not contrib. I don't
> think I understand what the underlying principal is supposed to be
> here. If you or anyone else knows, please enlighten me.

PGXS defines it as:

# HEADERS_$(MODULE) -- files to install into
# $(includedir_server)/$MODULEDIR/$MODULE; the value of $MODULE must be
# listed in MODULES or MODULE_big

where

# MODULEDIR -- subdirectory of $PREFIX/share into which DATA and DOCS files
# should be installed (if not set, default is "extension" if EXTENSION
# is set, or "contrib" if not)

And I mirrored that in meson.

Data seems to be wrong for headers, as that's

# DATA -- random files to install into $PREFIX/share/$MODULEDIR

> sepgsql uses dir_data / 'contrib'

Also, sepgsql installs an sql file, not an include.