Revert r10335, which had the NSE loader track require errors and handle them

specially. This was to hide the any errors raised by scripts using an openssl
module when OpenSSL itself wasn't available. For now this will be handled by
having each script check for openssl.

nse_init.cc

@@ -26,8 +26,6 @@ extern NmapOps o;
 extern int current_hosts;
 extern int errfunc;
 
-#define REQUIRE_ERRORS "require_error"
-
 /* int error_function (lua_State *L)
  *
  * Arguments:
@@ -111,26 +109,11 @@ static int loadfile (lua_State *L)
   lua_setfenv(L, -2); // set it
   if (lua_pcall(L, 0, 0, 0) != 0) // Call the function (loads globals)
   {
-    // Check for dependency errors
-    lua_getfield(L, LUA_REGISTRYINDEX, REQUIRE_ERRORS);
-    lua_pushvalue(L, -2); // the error
-    lua_gettable(L, -2);
-    if (lua_toboolean(L, -1)) // The error was thrown by require
-    {
-      if (o.verbose > 3 && !o.debugging)
-        error("%s: '%s' could not be loaded due to missing dependency '%s'",
-            SCRIPT_ENGINE, filename, lua_tostring(L, -1));
-      SCRIPT_ENGINE_DEBUGGING(
-        error("%s: '%s' threw a run time error and could not be loaded.\n%s",
-            SCRIPT_ENGINE, filename, lua_tostring(L, -3));
-      )
-    } else {
     error("%s: '%s' threw a run time error and could not be loaded.",
         SCRIPT_ENGINE, filename);
     SCRIPT_ENGINE_DEBUGGING(
-        error("%s", lua_tostring(L, -3));
+      error("%s", lua_tostring(L, -1));
     )
-    }
     return 0;
   }
 
@@ -248,30 +231,6 @@ static int init_setpath (lua_State *L)
   return 0;
 }
 
-/* int nse_require (lua_State *L)
- *
- * This hooks the standard require function to allow us to properly catch
- * dependency errors. Basically an error message is saved in the error table
- * (upvalue 1) that can be indexed later to check if it was unhandled by
- * the script (see loadfile in particular).
- */
-static int nse_require (lua_State *L)
-{
-  luaL_checkstring(L, 1); // ensure first argument is a string
-  lua_pushvalue(L, 1);
-  lua_insert(L, 1); // save a copy of the library name at stack bottom
-  lua_pushvalue(L, lua_upvalueindex(1)); // require function
-  lua_insert(L, 2);
-  if (lua_pcall(L, lua_gettop(L)-2, LUA_MULTRET, 0) != 0)
-  {
-    lua_pushvalue(L, -1); // the error message
-    lua_pushvalue(L, 1); // the library name that caused the error
-    lua_settable(L, lua_upvalueindex(2));
-    return lua_error(L);
-  }
-  return lua_gettop(L)-1; // omit the saved first argument
-}
-
 /* int init_lua (lua_State *L)
  *
  * Initializes the Lua State.
@@ -325,17 +284,6 @@ int init_lua (lua_State *L)
   lua_newtable(L);
   current_hosts = luaL_ref(L, LUA_REGISTRYINDEX);
 
-  lua_newtable(L); // nse_require error table
-  lua_createtable(L, 0, 1); // metatable
-  lua_pushliteral(L, "k");
-  lua_setfield(L, -2, "__mode"); // weak keys
-  lua_setmetatable(L, -2);
-  lua_getglobal(L, "require");
-  lua_pushvalue(L, -2); // nse_require error table
-  lua_pushcclosure(L, nse_require, 2);
-  lua_setglobal(L, "require");
-  lua_setfield(L, LUA_REGISTRYINDEX, REQUIRE_ERRORS); // save nse_require table
-
   return 0;
 }