3 files changed, 6 insertions, 2 deletions

diff --git a/lib/libalpm/alpm.c b/lib/libalpm/alpm.c
index f2a6270f..72b01a61 100644
--- a/lib/libalpm/alpm.c
+++ b/lib/libalpm/alpm.c
@@ -128,7 +128,7 @@ int SYMEXPORT alpm_release()
  * @param treename the name of the repository
  * @return a pmdb_t* on success (the value), NULL on error
  */
-pmdb_t SYMEXPORT *alpm_db_register(char *treename)
+pmdb_t SYMEXPORT *alpm_db_register(const char *treename)
 {
 	ALPM_LOG_FUNC;
 
diff --git a/lib/libalpm/alpm.h b/lib/libalpm/alpm.h
index 131ead3b..e2814281 100644
--- a/lib/libalpm/alpm.h
+++ b/lib/libalpm/alpm.h
@@ -148,7 +148,7 @@ alpm_list_t *alpm_option_get_syncdbs();
  * Databases
  */
 
-pmdb_t *alpm_db_register(char *treename);
+pmdb_t *alpm_db_register(const char *treename);
 int alpm_db_unregister(pmdb_t *db);
 
 const char *alpm_db_get_name(pmdb_t *db);
diff --git a/lib/libalpm/db.c b/lib/libalpm/db.c
index e5489973..16b09a47 100644
--- a/lib/libalpm/db.c
+++ b/lib/libalpm/db.c
@@ -186,6 +186,10 @@ pmdb_t *_alpm_db_register(const char *treename)
 
 	/* make sure the database directory exists */
 	dbpath = alpm_option_get_dbpath();
+	if(!dbpath) {
+		_alpm_log(PM_LOG_WARNING, _("database path is undefined"));
+			RET_ERR(PM_ERR_DB_OPEN, NULL);
+	}
 	snprintf(path, PATH_MAX, "%s%s", dbpath, treename);
 	if(stat(path, &buf) != 0 || !S_ISDIR(buf.st_mode)) {
 		_alpm_log(PM_LOG_DEBUG, _("database directory '%s' does not exist, creating it"),