Tolerate missing script.db; categories will not work.

nse_main.lua

@@ -711,9 +711,13 @@ local function get_chosen_scripts (rules)
   check_rules(rules);
 
   local db_env = {Entry = nil};
-  local db_closure = assert(loadfile(script_database_path, "t", db_env),
-    "database appears to be corrupt or out of date;\n"..
+  local db_closure = loadfile(script_database_path, "t", db_env)
+  if not db_closure then
+    log_write("stdout",
+      "NSE script database appears to be corrupt or out of date;\n"..
       "\tplease update using: nmap --script-updatedb");
+    db_closure = function () return end
+  end
 
   local chosen_scripts, files_loaded = {}, {};
   local used_rules, forced_rules = {}, {};
@@ -1316,7 +1320,13 @@ if script_database_update then
   local t, path = cnse.fetchfile_absolute('scripts/'); -- fetch script directory
   assert(t == 'directory', 'could not locate scripts directory');
   script_database_path = path.."script.db";
-  local db = assert(open(script_database_path, 'w'));
+  local db = open(script_database_path, 'w')
+  -- If user requested update with --script-updatedb, a failure here is fatal.
+  if cnse.scriptupdatedb then
+    assert(db, "Could not open script.db for writing")
+  end
+  -- If we're doing this for convenience only, it's ok to fail.
+  if db then
     local scripts = {};
     for f in lfs.dir(path) do
       if match(f, '%.nse$') then
@@ -1339,6 +1349,7 @@ if script_database_update then
     db:close();
     log_write("stdout", "Script Database updated successfully.");
   end
+end
 
 -- Load all user chosen scripts
 local chosen_scripts = get_chosen_scripts(rules);