db.table: check if driver is defined

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@65395 15284696-431f-4ddb-bdfa-cd5b030d7da7

db/db.tables/main.c

@@ -37,6 +37,9 @@ int main(int argc, char **argv)
 
     parse_command_line(argc, argv);
 
+    if (!parms.driver)
+        G_fatal_error(_("Database connection not defined. Run db.connect."));
+      
     driver = db_start_driver(parms.driver);
     if (driver == NULL)
 	G_fatal_error(_("Unable to start driver <%s>"), parms.driver);