Re: BUG #6715: 9.2b2 psql \ir does not understand leading ../

Josh Kupershmidt <schmiddy(at)gmail(dot)com> writes:
> On Tue, Jul 3, 2012 at 11:41 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> The get_parent_directory() call reduces "foo.sql" to an empty string,
>> which seems a tad bogus --- wouldn't "." be better? But in any case,
>> join_path_components() thinks it can process a "../" prefix of the
>> tail argument by stripping a directory name from the head argument,
>> and there's nothing there to strip. So IMO join_path_components()
>> is flat-out broken when applied to a non-absolute head path.
>> Not sure about what a useful solution would be.

> I may not have time to look at this today, but I think this behavior
> worked fine in the last version[1] of Gurjeet's \ir patch which I
> reviewed, which had different behavior for pathname normalization than
> what got committed.
> [1] http://archives.postgresql.org/message-id/BANLkTi=eW_nUH9195=9uPqF7Treg4UH7-g@mail.gmail.com

[ looks at that... ] Well, I can certainly see why Robert got rid of
that kluge in favor of using the path-manipulation functions we already
have. It looks like most of the existing uses of join_path_components
are using absolute paths (eg, the result of getcwd), which probably
explains why we've not previously noticed that it's not working
correctly in such cases.

On reflection I think that what we need to do is fix it so that it only
strips "../" from the tail string when there is a directory name
available to be stripped from the head string. Otherwise just stop
trimming.

regards, tom lane