+cat <<EOF > c_head3
+#include <notmuch-test.h>
+int main (int argc, char **argv) {
+ notmuch_status_t stat;
+ notmuch_database_t *db = NULL;
+EOF
+
+cat <<EOF > c_tail3
+ printf("db == NULL: %d\n", db == NULL);
+}
+EOF
+
+test_begin_subtest "open: database set to null on missing config"
+cat c_head3 - c_tail3 <<'EOF' | test_C ${MAIL_DIR}
+ notmuch_status_t st = notmuch_database_open_with_config(argv[1],
+ NOTMUCH_DATABASE_MODE_READ_ONLY,
+ "/nonexistent", NULL, &db, NULL);
+EOF
+cat <<EOF> EXPECTED
+== stdout ==
+db == NULL: 1
+== stderr ==
+EOF
+test_expect_equal_file EXPECTED OUTPUT
+
+test_begin_subtest "open: database set to null on missing config (env)"
+old_NOTMUCH_CONFIG=${NOTMUCH_CONFIG}
+export NOTMUCH_CONFIG="/nonexistent"
+cat c_head3 - c_tail3 <<'EOF' | test_C ${MAIL_DIR}
+ notmuch_status_t st = notmuch_database_open_with_config(argv[1],
+ NOTMUCH_DATABASE_MODE_READ_ONLY,
+ NULL, NULL, &db, NULL);
+EOF
+export NOTMUCH_CONFIG=${old_NOTMUCH_CONFIG}
+cat <<EOF> EXPECTED
+== stdout ==
+db == NULL: 1
+== stderr ==
+EOF
+test_expect_equal_file EXPECTED OUTPUT
+
+test_begin_subtest "create: database set to null on missing config"
+cat c_head3 - c_tail3 <<'EOF' | test_C ${MAIL_DIR} "/nonexistent"
+ notmuch_status_t st = notmuch_database_create_with_config(argv[1],argv[2], NULL, &db, NULL);
+EOF
+cat <<EOF> EXPECTED
+== stdout ==
+db == NULL: 1
+== stderr ==
+EOF
+test_expect_equal_file EXPECTED OUTPUT
+
+test_begin_subtest "create: database set to null on missing config (env)"
+old_NOTMUCH_CONFIG=${NOTMUCH_CONFIG}
+export NOTMUCH_CONFIG="/nonexistent"
+cat c_head3 - c_tail3 <<'EOF' | test_C ${MAIL_DIR}
+ notmuch_status_t st = notmuch_database_create_with_config(argv[1],
+ NULL, NULL, &db, NULL);
+EOF
+export NOTMUCH_CONFIG=${old_NOTMUCH_CONFIG}
+cat <<EOF> EXPECTED
+== stdout ==
+db == NULL: 1
+== stderr ==
+EOF
+test_expect_equal_file EXPECTED OUTPUT
+
+test_begin_subtest "load_config: database set non-null on missing config"
+cat c_head3 - c_tail3 <<'EOF' | test_C ${MAIL_DIR} "/nonexistent"
+ notmuch_status_t st = notmuch_database_load_config(argv[1],argv[2], NULL, &db, NULL);
+EOF
+cat <<EOF> EXPECTED
+== stdout ==
+db == NULL: 0
+== stderr ==
+EOF
+test_expect_equal_file EXPECTED OUTPUT
+
+test_begin_subtest "load_config: database non-null on missing config (env)"
+old_NOTMUCH_CONFIG=${NOTMUCH_CONFIG}
+export NOTMUCH_CONFIG="/nonexistent"
+cat c_head3 - c_tail3 <<'EOF' | test_C ${MAIL_DIR}
+ notmuch_status_t st = notmuch_database_load_config(argv[1], NULL, NULL, &db, NULL);
+EOF
+export NOTMUCH_CONFIG=${old_NOTMUCH_CONFIG}
+cat <<EOF> EXPECTED
+== stdout ==
+db == NULL: 0
+== stderr ==
+EOF
+test_expect_equal_file EXPECTED OUTPUT
+
+test_begin_subtest "load_config: database set to NULL on fatal error"
+cat c_head3 - c_tail3 <<'EOF' | test_C
+ notmuch_status_t st = notmuch_database_load_config("relative", NULL, NULL, &db, NULL);
+EOF
+cat <<EOF> EXPECTED
+== stdout ==
+db == NULL: 1
+== stderr ==
+EOF
+test_expect_equal_file EXPECTED OUTPUT
+
+test_begin_subtest "open: database parameter overrides implicit config"
+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
+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
+