Re: Prevent switching branches when local modifications exist

[Junio C Hamano <gitster@pobox.com>]

Christoph Bartoschek <ponto@pontohonk.de> writes:

> Hi,
>
> how can I prevent that git allows me to switch branches when there are 
> uncommited local modifications?
>
> [14.1 (steiner_topo)]$ git checkout -b ergo
> Switched to a new branch 'ergo'
> [14.1 (ergo)]$ echo blub >> src/invtree.C
> [14.1 (ergo)]$ git checkout steiner_topo
> M       src/invtree.C
> Switched to branch 'steiner_topo'
> [14.1 (steiner_topo)]$ 
>
> How can the last checkout be prevented?

The question sounds similar to asking "How can I prevent 'rm -r'
from removing anything when I type it in my home directory."  It is
useful for 'rm -r' to remove everything recursively, but sometimes
you would want to prevent you from running it by mistake in a wrong
place. In general, there is no good direct solution for that.

A few usual ways people deal with this kind of issue are (1) to make
it easier to notice that they are "in a wrong place" (e.g. by having
the current directory in their prompt to avoid 'rm -r' in $HOME) and
training themselves to be careful, (2) to make it possible to
recover if that happens by mistake (e.g. by having .snapshot on the
filer).

For "checkout", an approach that corresponds to (1) is to have
branches and status in the prompt (available from git-completion).
Fortunately for (2) there isn't anything special necessary, as
checking out a different branch with "git checkout" does not lose
information, after creating and checking out the steiner_topo
branch, you can use checkout again to come back to ergo branch.