lib: clear error message on success in _choose_database_path

Previously we both found a database and returned a message saying that
the database could not be found (along with a success code). This
change should prevent spurious error output.

lib/open.cc

@@ -249,6 +249,11 @@ _choose_database_path (notmuch_database_t *notmuch,
 	return NOTMUCH_STATUS_NO_DATABASE;
     }
 
+    if (*message) {
+	free (*message);
+	*message = NULL;
+    }
+
     return NOTMUCH_STATUS_SUCCESS;
 }
 

test/T055-path-config.sh

@@ -376,7 +376,6 @@ EOF
 	   ;;
        home_mail|maildir_env)
 	   test_begin_subtest "No errors from config list ($config)"
-	   test_subtest_known_broken
 	   notmuch config list 2>OUTPUT 1>/dev/null
 	   test_expect_equal_file /dev/null OUTPUT
 	   ;;