No local cloning for insteadOf URLs

Hi there,

on Linux I'm using the config option url.[].insteadOf feature to clone
certain (very big) submodules from a local mirror instead of from remote.
The configuration is something like

[url "/home/sampleuser/mirrors/bigrepo.git"]
    insteadOf = git@remotehost:bigrepo.git

Cloning this repo with
    git clone git@remotehost:bigrepo.git
works fine, it is cloning from my local repo instead of from the remote one.

But: I was expecting the 'git clone' call to take into account that it
is cloning a local repository and create hard links to the packs of my
local mirror repository, but instead it copies the whole repo just as it
was a remote repository. This should get fixed, this 'git clone' call
should detect that it is cloning a local repository and create hard
links to the *.pack files.

When cloning the local mirror directly with
    git clone /home/sampleuser/mirrors/bigrepo.git
'git clone' automatically creates hard links to the local mirrors *.pack
files.


Cheers,

Hannes