From 6a45d8c7e9f66d04cf4916264da135def5c0549d Mon Sep 17 00:00:00 2001 From: Bryce Kwon Date: Sat, 7 Nov 2026 19:31:51 -1000 Subject: Add filename* for a download name past ASCII MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The plain, snapshot and blob pages sent a name such as café.txt raw in filename, which a client may read as ISO-8859-1. RFC 6266 has such a name sent again as filename*, percent-encoded in UTF-8, for a client that knows the form, with filename first for one that does not. The extended form carries UTF-8 alone, so a name that is not valid UTF-8 keeps the plain filename by itself. --- source/ui-shared.c | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) (limited to 'source/ui-shared.c') diff --git a/source/ui-shared.c b/source/ui-shared.c index 9e3757d..d2eec25 100644 --- a/source/ui-shared.c +++ b/source/ui-shared.c @@ -1385,6 +1385,30 @@ static int type_has_charset(const char *mimetype) ends_with(mimetype, "+xml"); } +/* + * Whether a download name goes out a second time as RFC 6266's filename*, + * which is so for a name past ASCII. That form carries UTF-8 alone, so a name + * that is not valid UTF-8 keeps the plain filename by itself. + */ +static int wants_ext_filename(const char *name) +{ + const unsigned char *p = (const unsigned char *)name; + size_t left = strlen(name); + int past_ascii = 0; + + while (left) { + size_t seq = *p < 0x80 ? 1 : cgit_utf8_seq_len(p, left); + + if (!seq) + return 0; + if (seq > 1) + past_ascii = 1; + p += seq; + left -= seq; + } + return past_ascii; +} + void cgit_print_http_headers(void) { ctx.page.headers_sent = 1; @@ -1408,7 +1432,14 @@ void cgit_print_http_headers(void) if (ctx.page.filename) { html("Content-Disposition: inline; filename=\""); html_header_arg_in_quotes(ctx.page.filename); - html("\"\n"); + html("\""); + // A client that knows filename* reads it in place of filename, + // which stays for one that does not. + if (wants_ext_filename(ctx.page.filename)) { + html("; filename*=UTF-8''"); + html_header_ext_value(ctx.page.filename); + } + html("\n"); } // An untrusted page serves repository bytes verbatim, so the browser is // told not to guess a type of its own from them and not to load -- cgit 2.12.1