agent: Fix passphrase cache lookups.

CACHE_MODE_ANY is supposed to match any cache mode except
CACHE_MODE_IGNORE, but the code used '==' to compare cache modes.

* agent/cache.c (cache_mode_equal): New function.
(agent_set_cache): Use the new function to compare cache modes.
(agent_get_cache): Likewise.
* tests/openpgp/Makefile.am (TESTS): Add new test.
* tests/openpgp/issue2015.scm: New file.

GnuPG-bug-id: 2015
Signed-off-by: Justus Winter <justus@g10code.com>

tests/openpgp/Makefile.am

@@ -81,6 +81,7 @@ TESTS = setup.scm \
 	use-exact-key.scm \
 	default-key.scm \
 	export.scm \
+	issue2015.scm \
 	finish.scm
 
 

tests/openpgp/issue2015.scm

@@ -0,0 +1,29 @@
+#!/usr/bin/env gpgscm
+
+;; Copyright (C) 2016 g10 Code GmbH
+;;
+;; This file is part of GnuPG.
+;;
+;; GnuPG is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 3 of the License, or
+;; (at your option) any later version.
+;;
+;; GnuPG is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with this program; if not, see <http://www.gnu.org/licenses/>.
+
+(load (with-path "defs.scm"))
+
+(info "Checking passphrase cache (issue2015)...")
+(call-check `(,(tool 'gpg-preset-passphrase)
+	      --preset --passphrase some_passphrase some_id))
+
+(let ((response (call-popen `(,(tool 'gpg-connect-agent))
+			    "GET_PASSPHRASE --no-ask some_id X X X")))
+  (unless (string=? response "OK 736F6D655F70617373706872617365\n")
+	  (error "Could not retrieve passphrase from cache:" response)))