Steps to reproduce this bug:
1. Open the context menu for the the search field and select "Add keyword for search" (may have other wording, I only have a German Browser).
2. Enter name and keyword and click "OK".
3. Enter the keyword and a word you want to search for in the address bar of Firefox.
Expected result:
Search result page
Actual result:
"Page not found".
This error occurs because there is an empty "id" parameter in the action attribute of the search form tag.
Fix:
Use DOKU_SCRIPT instead of wl() in tpl_searchform. (See attached patch.)