Stephen BoydEasiest way to trigger this is by putting á in the commit search box and then hitting enter. On git.kernel.org you get a 403 Forbidden. On gitweb.samba.org it works. I know that git.kernel.org is non-standard, but I can reproduce locally when I run instaweb (I think my system could be mis-configured though).
Even odder, in all cases the letter in the search box becomes mangled on the results page. Meaning searching again by hitting enter will not be the same (and actually makes the search box text even worse).