How do I override Git configuration options by command line parameters?

Question

I want to override certain Git configuration options (in my case http.proxy) when calling a Git command directly by using command line parameters. Is this possi

Answer 1

Note that there is a new feature regarding the ability to override (with the command git -c) a config:

You couldn't set a config to an empty string (git -c http.proxy= or any other foo.bar=), that is until git 2.1.2 (Sept 30th, 2014), and commit a789ca7 Junio C Hamano (gitster)

config: teach "git -c" to recognize an empty string

In a config file, you can do:

[foo]
bar

to turn the "foo.bar" boolean flag on, and you can do:

[foo]
bar=

to set "foo.bar" to the empty string.
However, git's "-c" parameter treats both:

git -c foo.bar

and

git -c foo.bar=

as the boolean flag, and there is no way to set a variable to the empty string.
This patch enables the latter form to do that.