Re: Expand the use of check_canonical_path() for more GUCs

On 2020-05-29 19:24, Robert Haas wrote:
> On Tue, May 19, 2020 at 7:02 AM Peter Eisentraut
> <peter(dot)eisentraut(at)2ndquadrant(dot)com> wrote:
>> That thread didn't resolve why check_canonical_path() is necessary
>> there. Maybe the existing uses could be removed?
>
> This first sentence of this reply seems worthy of particualr
> attention. We have to know what problem this is intended to fix before
> we try to decide in which cases it's needed. Otherwise, whether we add
> it everywhere or remove it everywhere, we'll only know that it's
> consistent, not that it's correct.

The archeology reveals that these calls where originally added to
canonicalize the data_directory and config_file settings (7b0f060d54),
but that was then moved out of guc.c to be done early during postmaster
startup (337ffcddba). The remaining calls of check_canonical_path() in
guc.c appear to be leftovers from a previous regime.

--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services