It was unclear whether the field was to be specified by the user of the
API.
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `helpers` member of the struct is a `string_list` of helpers. Each
string specifies an external helper which will be run, in order, to
either acquire or store credentials. See the section on credential
-helpers below.
+helpers below. This list is filled-in by the API functions
+according to the corresponding configuration variables before
+consulting helpers, so there usually is no need for a caller to
+modify the helpers field at all.
+
This struct should always be initialized with `CREDENTIAL_INIT` or
`credential_init`.