Re: Bug in canonicalize_path()

I have test the following on Windows and Linux:

Windows:
    C:\>cd Winnt

    C:\WINNT>cd C:\Temp\..\..\

    C:\>

Linux:
    $ cd /usr/../../
    $ pwd
    /

We should handle this correctly. 

1 Single dot in the path can be removed safety. (except the first one. e.g. ./usr/local)
2 Every double dot may need a removal of the last part of the path. (except the first one. e.g. ../local)
   And if there are not enough part left, keep the last part as it is.

We can even make it easier by adding step 0: make sure path is an absolute path.

----- Original Message ----- 
From: "Bruce Momjian" <pgman@candle.pha.pa.us>
To: "Tom Lane" <tgl@sss.pgh.pa.us>
Cc: "William ZHANG" <uniware@zedware.org>; <pgsql-patches@postgresql.org>
Sent: Friday, August 12, 2005 11:15 AM
Subject: Re: [PATCHES] Bug in canonicalize_path()


> Tom Lane wrote:
> > Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > > But what about "usr/local/../../.."?
> > 
> > What about it?  The case of /usr/local/../../.. is handled correctly,
> > and the case where it's an underspecified relative path doesn't seem
> > that interesting to me --- certainly that is not so important that we
> > should get the wrong answer on cases that *are* plausible.
> > 
> > Most of the uses of canonicalize_path are on paths that are required to
> > be absolute, anyway.
> > 
> > It wouldn't be too implausible to error out if pending_strips>0 after
> > exiting the loop.
> 
> I figured it would be best to leave it alone if we can't process it, but
> if you think it is more imporant to trim in cases like ../.., go ahead.
> 
> -- 
>   Bruce Momjian                        |  http://candle.pha.pa.us
>   pgman@candle.pha.pa.us               |  (610) 359-1001
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