Enter "martedì" in quicksearch. Press "search" or "quick search" button. Error message:

DBD::Pg::db selectcol_arrayref failed: ERROR:  invalid byte sequence for encoding "UTF8": 0xec273a
HINT:  This error can also happen if the byte sequence does not match the encoding expected by the server, which is controlled by "client_encoding". [for Statement "SELECT products.id FROM products WHERE POSITION(LOWER('martedì'::text) IN LOWER(products.name::text)::text) > 0"] at Bugzilla/Search.pm line 1269
	Bugzilla::Search::build_subselect('bugs.product_id', 'products.id', 'products', 'POSITION(LOWER(\'marted\x{ec}\'::text) IN LOWER(products.name::tex...') called at Bugzilla/Search.pm line 2063
	Bugzilla::Search::_product_nonchanged('Bugzilla::Search=HASH(0x3842878)', 'multi_fields', 'ARRAY(0x2e1e7a0)', 'sequence', 'SCALAR(0x2e53600)', 'ff', 'SCALAR(0x2e540c8)', 'wherepart', 'ARRAY(0x2e1e548)', ...) called at Bugzilla/Search.pm line 1160
	Bugzilla::Search::do_search_function('Bugzilla::Search=HASH(0x3842878)', 'HASH(0x3888090)') called at Bugzilla/Search.pm line 963
	Bugzilla::Search::init('Bugzilla::Search=HASH(0x3842878)') called at Bugzilla/Search.pm line 409
	Bugzilla::Search::new('Bugzilla::Search', 'fields', 'ARRAY(0x31ede68)', 'params', 'Bugzilla::CGI=HASH(0x2fb5b28)', 'order', 'ARRAY(0x3213098)') called at /srv/bugs.freedesktop.org/www/buglist.cgi line 840
For help, please send mail to the webmaster (sitewranglers@freedesktop.org), giving this error message and the time and date of the error.


The correct UTF-8 encoding is of 'ì' is c3 ac, and it is correct in the URL bar: https://bugs.freedesktop.org/buglist.cgi?quicksearch=marted%C3%AC
So bugzilla and/or its interface to PostgreSQL does something fishy to it.

By contrast, the advanced search deals OK with non-ASCII characters: try https://bugs.freedesktop.org/buglist.cgi?list_id=47710&short_desc=marted%C3%AC&query_format=advanced&short_desc_type=allwordssubstr