path: root/utf8.h
diff options
authorKirill Smelkov <>2013-03-07 10:55:07 (GMT)
committerJunio C Hamano <>2013-03-09 19:11:19 (GMT)
commit6cd3c0532772749bcf6c4688f34c8ecc65ecb655 (patch)
treee9cbd620a7e93668a04d87b2c0fd1a2017e2b3d5 /utf8.h
parent15999998fbda60552742275570947431b57108ae (diff)
format-patch: RFC 2047 says multi-octet character may not be split
Even though an earlier attempt (bafc478..41dd00bad) cleaned up RFC 2047 encoding, pretty.c::add_rfc2047() still decides where to split the output line by going through the input one byte at a time, and potentially splits a character in the middle. A subject line may end up showing like this: ".... fö?? bar". (instead of ".... föö bar".) if split incorrectly. RFC 2047, section 5 (3) explicitly forbids such beaviour Each 'encoded-word' MUST represent an integral number of characters. A multi-octet character may not be split across adjacent 'encoded- word's. that means that e.g. for Subject: .... föö bar encoding Subject: =?UTF-8?q?....=20f=C3=B6=C3=B6?= =?UTF-8?q?=20bar?= is correct, and Subject: =?UTF-8?q?....=20f=C3=B6=C3?= <-- NOTE ö is broken here =?UTF-8?q?=B6=20bar?= is not, because "ö" character UTF-8 encoding C3 B6 is split here across adjacent encoded words. To fix the problem, make the loop grab one _character_ at a time and determine its output length to see where to break the output line. Note that this version only knows about UTF-8, but the logic to grab one character is abstracted out in mbs_chrlen() function to make it possible to extend it to other encodings with the help of iconv in the future. Signed-off-by: Kirill Smelkov <> Signed-off-by: Junio C Hamano <>
Diffstat (limited to 'utf8.h')
1 files changed, 2 insertions, 0 deletions
diff --git a/utf8.h b/utf8.h
index 93ef600..465c01d 100644
--- a/utf8.h
+++ b/utf8.h
@@ -21,4 +21,6 @@ char *reencode_string(const char *in, const char *out_encoding, const char *in_e
#define reencode_string(a,b,c) NULL
+int mbs_chrlen(const char **text, size_t *remainder_p, const char *encoding);