Re: is_absolute_path incorrect on Windows

Bruce Momjian wrote:
> > However, it misses the case with for example E:foo, which is a perfectly
> > valid path on windows. Which isn't absolute *or* relative - it's relative
> > to the current directory on the E: drive. Which will be the same as the
> > current directory for the process *if* the process current directory is
> > on drive E:. In other cases, it's a different directory.
>
> I would argue that E:foo is always relative (which matches
> is_absolute_path()). If E: is the current drive of the process, it is
> relative, and if the current drive is not E:, it is relative to the last
> current drive on E: for that process, or the top level if there was no
> current drive. (Tested on XP.)
>
> There seem to be three states:
>
> 1. absolute - already tested by is_absolute_path()
> 2. relative to the current directory (current drive)
> 3. relative on a different drive
>
> We could probably develop code to test all three, but keep in mind that
> the path itself can't distinguish between 2 and 3, and while you can
> test the current drive, if the current drive changes, a 2 could become a
> 3, and via versa.

I have reviewed is_absolute_path() and have implemented
path_is_relative_and_below_cwd() to cleanly handle cases like 'E:abc' on
Win32; patch attached.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +