[PATCH 3/5] lib/open: document expectations for db on error, add tests

[David Bremner <david@tethera.net>]

It seems sensible to harmonize the behaviour with
n_d_open_with_config. In this commit we just assert the desired
behaviour.
---
 lib/notmuch.h          |  3 +++
 test/T590-libconfig.sh | 42 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 45 insertions(+)

diff --git a/lib/notmuch.h b/lib/notmuch.h
index 074fc682..571b8a87 100644
--- a/lib/notmuch.h
+++ b/lib/notmuch.h
@@ -489,6 +489,9 @@ notmuch_database_load_config (const char *database_path,
  *
  * For description of arguments, @see notmuch_database_open_with_config
  *
+ * In case of any failure, this function returns an error status and
+ * database to NULL.
+ *
  * @retval NOTMUCH_STATUS_SUCCESS: Successfully created the database.
  *
  * @retval NOTMUCH_STATUS_DATABASE_EXISTS: Database already exists, not created
diff --git a/test/T590-libconfig.sh b/test/T590-libconfig.sh
index ca70642c..b36653bf 100755
--- a/test/T590-libconfig.sh
+++ b/test/T590-libconfig.sh
@@ -892,4 +892,46 @@ db == NULL: 1
 EOF
 test_expect_equal_file EXPECTED OUTPUT
 
+test_begin_subtest "create: database set to null on missing config"
+test_subtest_known_broken
+test_C ${MAIL_DIR} "/nonexistent" <<EOF
+#include <notmuch-test.h>
+int main (int argc, char **argv) {
+  notmuch_status_t stat;
+  notmuch_database_t *db = NULL;
+
+  notmuch_status_t st = notmuch_database_create_with_config(argv[1],argv[2], NULL, &db, NULL);
+  printf("db == NULL: %d\n", db == NULL);
+}
+EOF
+cat <<EOF> EXPECTED
+== stdout ==
+db == NULL: 1
+== stderr ==
+EOF
+test_expect_equal_file EXPECTED OUTPUT
+
+test_begin_subtest "create: database set to null on missing config (env)"
+test_subtest_known_broken
+old_NOTMUCH_CONFIG=${NOTMUCH_CONFIG}
+NOTMUCH_CONFIG="/nonexistent"
+test_C ${MAIL_DIR} <<EOF
+#include <notmuch-test.h>
+int main (int argc, char **argv) {
+  notmuch_status_t stat;
+  notmuch_database_t *db = NULL;
+
+  notmuch_status_t st = notmuch_database_create_with_config(argv[1],
+							  NULL, NULL, &db, NULL);
+  printf("db == NULL: %d\n", db == NULL);
+}
+EOF
+NOTMUCH_CONFIG=${old_NOTMUCH_CONFIG}
+cat <<EOF> EXPECTED
+== stdout ==
+db == NULL: 1
+== stderr ==
+EOF
+test_expect_equal_file EXPECTED OUTPUT
+
 test_done
-- 
2.33.0