Starting out the reviews:
Jonathan Nieder wrote:
[...]
> configuration item to empty before giving it a new value. This is
> already documented by the documentation is hard to find ---
^^
s/by/but/
Sorry for the confusion.
[...]
> +++ b/Documentation/gitcredentials.txt
[...]
> @@ -162,6 +152,16 @@ helper::
> shell (so, for example, setting this to `foo --option=bar` will execute
> `git credential-foo --option=bar` via the shell. See the manual of
> specific helpers for examples of their use.
> ++
> +If there are multiple instances of the `credential.helper` configuration
> +variable, each helper will be tried in turn, and may provide a username,
> +password, or nothing. Once Git has acquired both a username and a
> +password, no more helpers will be tried.
> ++
> +If `credential.helper` is configured to the empty string, this resets
> +the helper list to empty (so you may override a helper set by a
> +lower-priority config file by configuring the empty-string helper,
It's not necessarily obvious to a new user what "lower-priority" means.
Since this text is an example, maybe it should say something like "so,
for example, you can override a helper set in /etc/gitconfig by
configuring the empty-string helper followed by whatever set of
helpers you would like in ~/.gitconfig".
That's orthogonal to this patch but it should be straightforward to
roll in if it makes sense.
Thanks,
Jonathan