Whats wrong in this mod rewrite code

One of my friend is facing some issues with this code

   RewriteEngine on
   RewriteRule    ^$ app/webroot/    [L]
   RewriteRule    (.*) app/webroot/$1 [L]

Code (markup):

Whats wrong in this code ??

 

Any help is appreciated ??

 

First of all you are using a wildcard to match anything on your second rewrite, imo bad

 

Whats the solution ? if i remove last line i dont get an internal error