Fix a bug which caused some NSE scripts to fail, due to the absence of

the NSE SCRIPT_NAME environment variable when the scripts are loaded.
Reported by Michael Pattrick.

CHANGELOG

@@ -1,5 +1,9 @@
 # Nmap Changelog ($Id$); -*-text-*-
 
+o [NSE] Fixed a bug which caused some NSE scripts to fail, due to the
+  absence of the NSE SCRIPT_NAME environment variable when the scripts
+  are loaded. Michael Pattrick reported the problem. [Djalal]
+
 o Fixed some inconsistencies in nmap-os-db reported by Xavier Sudre
   from netVigilance.
 

docs/scripting.xml

@@ -1252,6 +1252,8 @@ action refer to <xref linkend="nse-tutorial-action"/>.
               <literal>"prerule"</literal>, <literal>"hostrule"</literal>, 
               <literal>"portrule"</literal> or 
               <literal>"postrule"</literal>.
+              This variable is only available after the evaluation of
+              the rule functions.
             </para>
           </listitem>
         </varlistentry>

nse_main.lua

@@ -303,6 +303,7 @@ do
     local script_type = assert(NSE_SCRIPT_RULES[rule]);
     if not self[rule] then return nil end -- No rule for this script?
     local file_closure = self.file_closure;
+    -- Rebuild the environment for the running thread.
     local env = {
         SCRIPT_PATH = self.filename,
         SCRIPT_NAME = self.short_basename,
@@ -366,10 +367,15 @@ do
           "Warning: Loading '%s' -- the recommended file extension is '.nse'.",
           filename);
     end
+    local basename = match(filename, "[/\\]([^/\\]-)$") or filename;
+    local short_basename = match(filename, "[/\\]([^/\\]-)%.nse$") or
+                       match(filename, "[/\\]([^/\\]-)%.[^.]*$") or
+                       filename;
     local file_closure = assert(loadfile(filename));
     -- Give the closure its own environment, with global access
     local env = {
-      filename = filename,
+      SCRIPT_PATH = filename,
+      SCRIPT_NAME = short_basename,
       dependencies = {},
     };
     setmetatable(env, {__index = _G});
@@ -412,11 +418,9 @@ do
     -- Return the script
     local script = {
       filename = filename,
-      basename = match(filename, "[/\\]([^/\\]-)$") or filename,
+      basename = basename,
-      short_basename = match(filename, "[/\\]([^/\\]-)%.nse$") or
+      short_basename = short_basename,
-                       match(filename, "[/\\]([^/\\]-)%.[^.]*$") or
+      id = match(filename, "^.-[/\\]([^\\/]-)%.nse$") or short_basename,
-                       filename,
-      id = match(filename, "^.-[/\\]([^\\/]-)%.nse$") or filename,
       file_closure = file_closure,
       prerule = prerule,
       hostrule = hostrule,

scripts/ssh-hostkey.nse

@@ -51,7 +51,7 @@ else
   portrule = function() return false end
   action = function() end
   stdnse.print_debug( 3, "Skipping %s script because OpenSSL is missing.",
-      filename)
+      SCRIPT_NAME)
   return;
 end