added gcrypt.publish-participants configuration

Fixes https://github.com/blake2-ppc/git-remote-gcrypt/issues/9

README.rst

@@ -60,6 +60,17 @@ 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-publish-participants``
+    ..
+``gcrypt.publish-participants``
+    By default, the gpg key ids of the participants are obscured by
+    encrypting using `gpg -R`. Setting this option to `true` disables
+    that security measure.
+
+    The problem with using `gpg -R` is that to decrypt, gpg tries each
+    available secret key in turn until it finds a usable key.
+    This can result in unncessary passphrase prompts.
+
 ``remote.<name>.gcrypt-signingkey``
     ..
 ``user.signingkey``
@@ -68,6 +79,7 @@ The following ``git-config(1)`` variables are supported:
     part of the participant list. You may use the per-remote version
     to sign different remotes using different keys.
 
+
 Environment Variables
 =====================
 

git-remote-gcrypt

@@ -406,6 +406,8 @@ read_config()
 		git config --path user.signingkey || :)
 	conf_part=$(git config --get "remote.$NAME.gcrypt-participants" '.+' ||
 		    git config --get gcrypt.participants '.+' || :)
+	Conf_pubish_participants=$(git config --get --bool "remote.$NAME.gcrypt-publish-participants" '.+' ||
+		git config --get --bool gcrypt.publish-participants || :)
 
 	# Figure out which keys we should encrypt to or accept signatures from
 	if isnull "$conf_part" || iseq "$conf_part" simple
@@ -440,7 +442,13 @@ read_config()
 		}
 		# Check 'E'ncrypt capability
 		cap_=$(xfeed "$r_keyinfo" cut -f 12 -d :)
-		iseq "${cap_#*E}" "$cap_" || Recipients="$Recipients -R $keyid_"
+		if ! iseq "${cap_#*E}" "$cap_"; then
+			if [ "$Conf_pubish_participants" = true ]; then
+				Recipients="$Recipients -r $keyid_"
+			else
+				Recipients="$Recipients -R $keyid_"
+			fi
+		fi
 	done
 
 	if isnull "$Recipients"