Re: [PATCH] Fix Q-encoded multi-octet-char split in email.
On Tue, Jul 03, 2012 at 10:41:37AM +0900, katsu wrote:
Show 19 quoted lines
> Issue: Email subject written in multi-octet language like japanese cannot
> be displayed in correct at destinations's email client, because the
> Q-encoded subject which is longer than 78 octets is split by a octet not by
> a character at line breaks.
> e.g.)
> "=?utf-8?q? [PATCH] ... =E8=83=86=E8=81=A9?="
> |
> V
> "=?utf-8?q? [PATCH] ... =E8=83=86=E8?="
> "=?utf-8?q?=81=A9=?"
>
> Changes: Add a judge if a character is an part of utf-8 muti-octet, and
> split the characters by a character not by a octet at line breaks in
> function add_rfc2407() in pretty.c. Like following.
>
> "=?utf-8?q? [PATCH] ... =E8=83=86?="
> "=?utf-8?q?=E8=81=A9=?"
>
> Signed-off-by: Takeharu Katsuyama <tkatsu.ne@gmail.com>
Yeah, we definitely don't handle that properly according to the rfc. This patch is is going in the right direction, but I have a few comments:
Show 12 quoted lines
> --- a/pretty.c
> +++ b/pretty.c
> @@ -272,6 +272,12 @@ static void add_rfc2047(struct strbuf *sb, const char *line, int len,
> static const int max_length = 78; /* per rfc2822 */
> int i;
> int line_len;
> + int utf_ctr, use_utf;
> +
> + if (!strcmp(encoding, "UTF-8") || !strcmp(encoding, "utf-8"))
> + use_utf = 1;
> + else
> + use_utf = 0;
Please use is_encoding_utf8, which handles both of these spellings, as well as "utf8" and "UTF8" (it also handles encoding==NULL; I don't think that can happen in this code path, but it is nice to be defensive).
Show 30 quoted lines
> @@ -293,10 +299,31 @@ needquote:
> strbuf_grow(sb, len * 3 + strlen(encoding) + 100);
> strbuf_addf(sb, "=?%s?q?", encoding);
> line_len += strlen(encoding) + 5; /* 5 for =??q? */
> + utf_ctr = 0;
> for (i = 0; i < len; i++) {
> unsigned ch = line[i] & 0xFF;
>
> - if (line_len >= max_length - 2) {
> + /*
> + * Judge if it is an utf-8 char, to avoid inserting newline
> + * in the middle of utf-8 char code.
> + */
> + if (use_utf) {
> + if (ch >= 0xC2 && ch <= 0xDF) /* 1'st byte of 2-bytes utf-8 */
> + utf_ctr = 1;
> + else if (ch >= 0xE0 && ch <= 0xEF) /* 3-bytes utf-8 */
> + utf_ctr = 2;
> + else if (ch >= 0xF0 && ch <= 0xF7) /* 4-bytes utf-8 */
> + utf_ctr = 3;
> + else if (ch >= 0xF8 && ch <= 0xFB) /* 5-bytes utf-8 */
> + utf_ctr = 4;
> + else if (ch >= 0xFC && ch <= 0xFD) /* 6-bytes utf-8 */
> + utf_ctr = 5;
> + else if (ch >= 0x80 && ch <= 0xBF) /* 2'nd to 6'th byte of utf-8 */
> + utf_ctr--;
> + else
> + utf_ctr = 0;
> + }
> + if (line_len >= (max_length - 2 - utf_ctr *3)) {Can we re-use utf8_width here instead of rewriting these rules?
-Peff
