Index: nse_main.lua
===================================================================
--- nse_main.lua	(revision 27267)
+++ nse_main.lua	(working copy)
@@ -350,7 +350,7 @@
       print_debug(1,
     "A thread for %s yielded unexpectedly in the file or %s function:\n%s\n",
           self.filename, rule, traceback(co));
-    elseif s and rule_return then
+    elseif s and (rule_return or self.forced_to_run) then
       local thread = {
         co = co,
         env = env,
@@ -385,9 +385,12 @@
   -- Creates a new Script Class for the script.
   -- Arguments:
   --   filename  The filename (path) of the script to load.
+  --   selected_by_name  If the script was selected by name.
+  --   forced_to_run  If the script was selected to run
+  --                  regardless of its rule.
   -- Returns:
   --   script  The script (class) created.
-  function Script.new (filename, selected_by_name)
+  function Script.new (filename, selected_by_name, forced_to_run)
     assert(type(filename) == "string", "string expected");
     if not find(filename, "%.nse$") then
       log_error(
@@ -395,11 +398,14 @@
           filename);
     end
     local basename = match(filename, "([^/\\]+)$") or filename;
-    if selected_by_name then
-      print_debug(2, "Script %s was selected by name.", basename);
-    end
     local short_basename = match(filename, "([^/\\]+)%.nse$") or
         match(filename, "([^/\\]+)%.[^.]*$") or filename;
+    if debugging() > 1 then
+      print_debug(2, "Script %s was selected by %s%s.",
+          basename,
+          selected_by_name and "name" or "category",
+          forced_to_run and " and forced to run" or "");
+    end
     local file_closure = assert(loadfile(filename));
     -- Give the closure its own environment, with global access
     local env = {
@@ -470,7 +476,9 @@
       license = rawget(env, "license"),
       dependencies = rawget(env, "dependencies"),
       threads = {},
+      -- Make sure that the following are boolean types.
       selected_by_name = not not selected_by_name,
+      forced_to_run = not not forced_to_run,
     };
     return setmetatable(script, {__index = Script, __metatable = Script});
   end
@@ -500,7 +508,8 @@
     "database appears to be corrupt or out of date;\n"..
     "\tplease update using: nmap --script-updatedb");
 
-  local chosen_scripts, entry_rules, used_rules, files_loaded = {}, {}, {}, {};
+  local chosen_scripts, files_loaded = {}, {};
+  local entry_rules, used_rules, forced_rules = {}, {}, {};
 
   -- Tokens that are allowed in script rules (--script)
   local protected_lua_tokens = {
@@ -508,28 +517,52 @@
     ["or"] = true,
     ["not"] = true,
   };
+
+  -- Was this category selection forced to run (e.g. "+script").
+  -- Return:
+  --    Boolean: True if it's forced otherwise false.
+  --    String: The new cleaned string.
+  local function is_forced_set (str)
+    local substr, count = gsub(str, "^%+", "");
+    if count > 0 then
+      return true, substr;
+    end
+    return false, str;
+  end
+
   -- Globalize all names in str that are not protected_lua_tokens
   local function globalize (str)
     local lstr = lower(str);
     if protected_lua_tokens[lstr] then
       return lstr;
     else
-      return 'm("'..str..'")';
+      local forced, substr = is_forced_set(str);
+      if forced then
+        forced_rules[substr] = true;
+      end
+      return 'm("'..substr..'")';
     end
   end
 
   for i, rule in ipairs(rules) do
     rule = match(rule, "^%s*(.-)%s*$"); -- strip surrounding whitespace
-    used_rules[rule] = false; -- has not been used yet
+    local original_rule = rule;
     -- Globalize all `names`, all visible characters not ',', '(', ')', and ';'
     local globalized_rule =
         gsub(rule, "[\033-\039\042-\043\045-\058\060-\126]+", globalize);
+    -- Remove the force flag
+    local forced, subrule = is_forced_set(rule);
+    if forced then
+      rule = subrule;
+    end
+    used_rules[rule] = false; -- has not been used yet
     -- Precompile the globalized rule
     local compiled_rule, err = loadstring("return "..globalized_rule, "rule");
     if not compiled_rule then
       err = err:match("rule\"]:%d+:(.+)$"); -- remove (luaL_)where in code
-      error("Bad script rule:\n\t"..rule.." -> "..err);
+      error("Bad script rule:\n\t"..original_rule.." -> "..err);
     end
+    -- These are used to reference and check all the rules later.
     entry_rules[globalized_rule] = {
       original_rule = rule,
       compiled_rule = compiled_rule,
@@ -555,13 +588,21 @@
     -- whether it was so that scripts so selected can get a verbosity boost.
     -- See nmap.verbosity.
     local selected_by_name = false;
+
+    -- Force the script to run (e.g: "+script").
+    local forced = false;
+
     -- A matching function for each script rule.
     -- If the pattern directly matches a category (e.g. "all"), then
     -- we return true. Otherwise we test if it is a filename or if
     -- the script_entry.filename matches the pattern.
     local function m (pattern)
+      -- Check the pattern to see if scripts were forced to run
+      forced = not not forced_rules[pattern];
+
       -- Check categories
       if r_categories[lower(pattern)] then return true end
+
       -- Check filename with wildcards
       pattern = gsub(pattern, "%.nse$", ""); -- remove optional extension
       pattern = gsub(pattern, "[%^%$%(%)%%%.%[%]%+%-%?]", "%%%1"); -- esc magic
@@ -569,17 +610,21 @@
       pattern = "^"..pattern.."$"; -- anchor to beginning and end
       local found = not not find(escaped_basename, pattern);
       selected_by_name = selected_by_name or found;
+
       return found;
     end
     local env = {m = m};
 
     for globalized_rule, rule_table in pairs(entry_rules) do
-      if setfenv(rule_table.compiled_rule, env)() then -- run the compiled rule
+      -- Run the compiled category selection
+      if setfenv(rule_table.compiled_rule, env)() then
+        -- do not break so other rules can be marked as used
         used_rules[rule_table.original_rule] = true;
         local t, path = cnse.fetchscript(filename);
         if t == "file" then
           if not files_loaded[path] then
-            chosen_scripts[#chosen_scripts+1] = Script.new(path, selected_by_name);
+            local script = Script.new(path, selected_by_name, forced);
+            chosen_scripts[#chosen_scripts+1] = script;
             files_loaded[path] = true;
             -- do not break so other rules can be marked as used
           end
@@ -597,6 +642,7 @@
   -- Now load any scripts listed by name rather than by category.
   for rule, loaded in pairs(used_rules) do
     if not loaded then -- attempt to load the file/directory
+      local forced = not not forced_rules[rule];
       local t, path = cnse.fetchscript(rule);
       if t == nil then -- perhaps omitted the extension?
         t, path = cnse.fetchscript(rule..".nse");
@@ -604,14 +650,15 @@
       if t == nil then
         error("'"..rule.."' did not match a category, filename, or directory");
       elseif t == "file" and not files_loaded[path] then
-        local script = Script.new(path, true);
+        local script = Script.new(path, true, forced);
         chosen_scripts[#chosen_scripts+1] = script;
         files_loaded[path] = true;
       elseif t == "directory" then
         for f in cnse.dir(path) do
           local file = path .."/".. f
           if find(f, "%.nse$") and not files_loaded[file] then
-            chosen_scripts[#chosen_scripts+1] = Script.new(file);
+            local script = Script.new(file, false, forced);
+            chosen_scripts[#chosen_scripts+1] = script;
             files_loaded[file] = true;
           end
         end