add remote.<name>.gcrypt-signingkey config

This is needed by git-annex assistant when it sets up a gcrypt repository,
to ensure that the gpg key it was asked to use to encrypt the repo is the
same key used to sign it. If it's not, pulling from the repo won't work,
due to git-remote-gcrypt's "Only accepting signatories" check.

The user may have a global user.signingkey setting (I do), but be setting
up a different special-purpose key for encrypting their git repo. The
git-annex assistant cannot mess with the global value, so needs this to
override it.

2 files changed, 8 insertions, 4 deletions

diff --git a/README.rst b/README.rst
index f177913..6fc4636 100644
--- a/README.rst
+++ b/README.rst
@@ -60,10 +60,13 @@ The following ``git-config(1)`` variables are supported:
     The ``gcrypt-participants`` setting on the remote takes precedence
     over the repository variable ``gcrypt.participants``.
 
+``remote.<name>.gcrypt-signingkey``
+    ..
 ``user.signingkey``
-    (From regular git configuration) The key to use for signing.  You
-    should set ``user.signingkey`` if your default signing key is not
-    part of the participant list.
+    (The latter from regular git configuration) The key to use for signing.
+    You should set ``user.signingkey`` if your default signing key is not
+    part of the participant list. You may use the per-remote version
+    to sign different remotes using different keys.
 
 Environment Variables
 =====================
diff --git a/git-remote-gcrypt b/git-remote-gcrypt
index 182c5cb..bf75777 100755
--- a/git-remote-gcrypt
+++ b/git-remote-gcrypt
@@ -389,7 +389,8 @@ make_new_repo()
 read_config()
 {
 	local recp_= r_keyinfo= cap_= conf_part= good_sig= signers_=
-	Conf_signkey=$(git config --path user.signingkey || :)
+	Conf_signkey=$(git config --get "remote.$NAME.gcrypt-signingkey" '.+' ||
+		git config --path user.signingkey || :)
 	conf_part=$(git config --get "remote.$NAME.gcrypt-participants" '.+' ||
 		    git config --get gcrypt.participants '.+' || :)