Re: branch.autoSetupMerge option for "if name matches only"?

[Xavier Morel <xmo@odoo.com>]

I found this message when trying to see if someone had already suggested 
something along those lines.

In fact I would be even more restrictive: what I wanted to propose was 
to only automatically setup the merge on implicit remote tracking 
branches, that is:

     git switch foo

if there is no such branch locally will look for the corresponding 
branch in the remotes, and will create a matching local one. In that 
case it makes a lot of sense to create a remote-tracking branch: when 
implicitly checking out a remote branch, it's likely the goal is to 
track it.

The issue is that

     git switch -c bar foo

will do the same, despite explicitely creating a differently named 
branch, which is probably some sort of feature which needs to be 
remote-ed somewhere else. If this issue is not caught immediately it is 
possible to push directly upstream by mistake.

Upon reading the documentation of `git switch` I actually believed this 
would behave correctly given `autoSetupMerge=false`:

     --guess, --no-guess
         If <branch> is not found but there does exist a tracking branch 
in exactly one remote (call it <remote>) with
         a matching name, treat as equivalent to

             $ git switch -c <branch> --track <remote>/<branch>

Because `--guess` is the default for the `git switch <name>` form, this 
description made me believe the tracking would be forced.

Sadly it is not so, setting `autoSetupMerge=false` will also disable 
automatic remote-tracking on guessed branch.

As far as I'm concerned, `git switch` actually behaving as documented 
would resolve the entire issue (especially if it were possible to 
disable `git checkout` somehow, such that I would have to force muscle 
memory).

This is made more annoying because

     git switch -t foo

*does not work*, frustratingly (if as documented, this time) `-t` 
implies `-c`. So it's not even possible to remember to type `git switch 
-t remotebranch` and then live happily with `autoSetupMerge=false`. This 
makes `autoSetupMerge=false` a lot more frustrating that necessary.