completion of '../' with symlink component in CWD path

[Felix]

I just encountered the following behaviour. Set up a directory
structure like:

mkdir basedir
cd basedir
mkdir -p dir1/dir2
ln -s dir1/dir2 dir2link
cd dir2link

now, you're sitting in dir2link, and you type:

cd ../

and hit the Tab key. The possible completions are shown as 'dir1' and
'dir2link', i.e. the contents of basedir. And if you finish the command
as:

cd ../dir1

It will change to dir1. However, if you instead do this while your
current working directory is 'dir2link':

echo foo > ../dir1/bar

It fails with "No such file or directory".

The problem is that some commands are "smart" and "know" how you
got to your current working dir -- bash knows that you're in a symlink
and that the parent dir of the *symlink* (not the actual directory
you're in) is 'basedir'.

However, this is not the literal meaning of the '..' directory entry
according to the filesystem. Some parts of bash use the "smart"
behaviour (cd and completion), and some parts use what the filesystem
actually says, i.e. that '..' inside 'dir2' is 'dir1', not
'basedir' (output redirection).

...after thinking about this, I've managed to confuse myself and am not
sure which behaviour should be considered correct.

~Felix.