[PATCH] Fix Q-encoded multi-octet-char split in email.
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>
---
pretty.c | 29 ++++++++++++++++++++++++++++-
1 files changed, 28 insertions(+), 1 deletions(-)
mode change 100644 => 100755 pretty.c
diff --git a/pretty.c b/pretty.c
old mode 100644
new mode 100755
index 8b1ea9f..266a8fe
--- 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;
/* How many bytes are already used on the current line? */
for (i = sb->len - 1; i >= 0; i--)
@@ -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)) {
strbuf_addf(sb, "?=\n =?%s?q?", encoding);
line_len = strlen(encoding) + 5 + 1; /* =??q? plus SP */
}
--
1.7.9