+test_begin_subtest "open: database parameter overrides implicit config"
+cp $NOTMUCH_CONFIG ${NOTMUCH_CONFIG}.bak
+notmuch config set database.path ${MAIL_DIR}/nonexistent
+cat c_head3 - c_tail3 <<'EOF' | test_C ${MAIL_DIR}
+ const char *path = NULL;
+ notmuch_status_t st = notmuch_database_open_with_config(argv[1],
+ NOTMUCH_DATABASE_MODE_READ_ONLY,
+ NULL, NULL, &db, NULL);
+ printf ("status: %d\n", st);
+ path = notmuch_database_get_path (db);
+ printf ("path: %s\n", path ? path : "(null)");
+EOF
+cp ${NOTMUCH_CONFIG}.bak ${NOTMUCH_CONFIG}
+cat <<EOF> EXPECTED
+== stdout ==
+status: 0
+path: MAIL_DIR
+db == NULL: 0
+== stderr ==
+EOF
+notmuch_dir_sanitize < OUTPUT > OUTPUT.clean
+test_expect_equal_file EXPECTED OUTPUT.clean
+
+cat <<EOF > c_body
+ notmuch_status_t st = notmuch_database_open_with_config(NULL,
+ NOTMUCH_DATABASE_MODE_READ_ONLY,
+ "", NULL, &db, NULL);
+ printf ("status == SUCCESS: %d\n", st == NOTMUCH_STATUS_SUCCESS);
+ if (db) {
+ const char *mail_root = NULL;
+ mail_root = notmuch_config_get (db, NOTMUCH_CONFIG_MAIL_ROOT);
+ printf ("mail_root: %s\n", mail_root ? mail_root : "(null)");
+ }
+EOF
+
+cat <<EOF> EXPECTED.common
+== stdout ==
+status == SUCCESS: 0
+db == NULL: 1
+== stderr ==
+EOF
+
+test_begin_subtest "open/error: config=empty with no mail root in db "
+old_NOTMUCH_CONFIG=${NOTMUCH_CONFIG}
+unset NOTMUCH_CONFIG
+cat c_head3 c_body c_tail3 | test_C
+export NOTMUCH_CONFIG=${old_NOTMUCH_CONFIG}
+notmuch_dir_sanitize < OUTPUT > OUTPUT.clean
+test_expect_equal_file EXPECTED.common OUTPUT.clean
+
+test_begin_subtest "open/error: config=empty with no mail root in db (xdg)"
+old_NOTMUCH_CONFIG=${NOTMUCH_CONFIG}
+unset NOTMUCH_CONFIG
+backup_database
+mkdir -p home/.local/share/notmuch
+mv mail/.notmuch home/.local/share/notmuch/default
+cat c_head3 c_body c_tail3 | test_C
+restore_database
+export NOTMUCH_CONFIG=${old_NOTMUCH_CONFIG}
+notmuch_dir_sanitize < OUTPUT > OUTPUT.clean
+test_expect_equal_file EXPECTED.common OUTPUT.clean
+