[PATCH 13/22] lib/open: Use check for existing database by trial opening

[David Bremner <david@tethera.net>]

This is a bit heavyweight for now, but it will make more sense when we
check multiple locations for the Xapian database.
---
 lib/open.cc                | 61 +++++++++++++++++++++++++++++---------
 test/T360-symbol-hiding.sh |  2 +-
 2 files changed, 48 insertions(+), 15 deletions(-)

diff --git a/lib/open.cc b/lib/open.cc
index 54e71fec..956d50b9 100644
--- a/lib/open.cc
+++ b/lib/open.cc
@@ -232,6 +232,51 @@ _alloc_notmuch ()
     return notmuch;
 }
 
+static notmuch_status_t
+_trial_open (const char *xapian_path, char **message_ptr)
+{
+    try {
+	Xapian::Database db (xapian_path);
+    } catch (const Xapian::DatabaseOpeningError &error) {
+	IGNORE_RESULT (asprintf (message_ptr,
+				 "Cannot open Xapian database at %s: %s\n",
+				 xapian_path,
+				 error.get_msg ().c_str ()));
+	return NOTMUCH_STATUS_PATH_ERROR;
+    } catch (const Xapian::Error &error) {
+	IGNORE_RESULT (asprintf (message_ptr,
+				 "A Xapian exception occurred opening database: %s\n",
+				 error.get_msg ().c_str ()));
+	return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
+    }
+    return NOTMUCH_STATUS_SUCCESS;
+}
+
+static notmuch_status_t
+_choose_xapian_path (void *ctx, const char *database_path, const char **xapian_path,
+		     char **message_ptr)
+{
+    notmuch_status_t status;
+    const char *trial_path, *notmuch_path;
+
+    status = _db_dir_exists (database_path, message_ptr);
+    if (status)
+	goto DONE;
+
+    notmuch_path = talloc_asprintf (ctx, "%s/.notmuch", database_path);
+    status = _db_dir_exists (notmuch_path, message_ptr);
+    if (status)
+	goto DONE;
+
+    trial_path = talloc_asprintf (ctx, "%s/xapian", notmuch_path);
+    status = _trial_open (trial_path, message_ptr);
+
+  DONE:
+    if (status == NOTMUCH_STATUS_SUCCESS)
+	*xapian_path = trial_path;
+    return status;
+}
+
 static void
 _set_database_path (notmuch_database_t *notmuch,
 		    const char *database_path)
@@ -410,7 +455,6 @@ notmuch_database_open_with_config (const char *database_path,
     notmuch_status_t status = NOTMUCH_STATUS_SUCCESS;
     void *local = talloc_new (NULL);
     notmuch_database_t *notmuch = NULL;
-    char *notmuch_path;
     char *message = NULL;
     GKeyFile *key_file = NULL;
 
@@ -426,27 +470,16 @@ notmuch_database_open_with_config (const char *database_path,
 					 &message)))
 	goto DONE;
 
-    _set_database_path (notmuch, database_path);
-
     status = _db_dir_exists (database_path, &message);
     if (status)
 	goto DONE;
 
-    if (! (notmuch_path = talloc_asprintf (local, "%s/%s", database_path, ".notmuch"))) {
-	message = strdup ("Out of memory\n");
-	status = NOTMUCH_STATUS_OUT_OF_MEMORY;
-	goto DONE;
-    }
+    _set_database_path (notmuch, database_path);
 
-    status = _db_dir_exists (notmuch_path, &message);
+    status = _choose_xapian_path (local, database_path, &notmuch->xapian_path, &message);
     if (status)
 	goto DONE;
 
-    if (! (notmuch->xapian_path = talloc_asprintf (notmuch, "%s/%s", notmuch_path, "xapian"))) {
-	status = NOTMUCH_STATUS_OUT_OF_MEMORY;
-	goto DONE;
-    }
-
     status = _finish_open (notmuch, profile, mode, key_file, &message);
 
   DONE:
diff --git a/test/T360-symbol-hiding.sh b/test/T360-symbol-hiding.sh
index 729b9d72..642457bf 100755
--- a/test/T360-symbol-hiding.sh
+++ b/test/T360-symbol-hiding.sh
@@ -17,7 +17,7 @@ $TEST_DIRECTORY/symbol-test ${PWD}/fakedb ${PWD}/nonexistent 2>&1 \
 	| notmuch_dir_sanitize | sed -e "s,\`,\',g" -e "s,No [^[:space:]]* database,No XXXXXX database,g" > OUTPUT
 
 cat <<EOF > EXPECTED
-A Xapian exception occurred opening database: Couldn't stat 'CWD/fakedb/.notmuch/xapian'
+Cannot open Xapian database at CWD/fakedb/.notmuch/xapian: Couldn't stat 'CWD/fakedb/.notmuch/xapian'
 caught No XXXXXX database found at path 'CWD/nonexistent'
 EOF
 test_expect_equal_file EXPECTED OUTPUT
-- 
2.30.1