Subject and identity headers may be arbitrarily long. In the
past, we just assumed that single-line headers would be
reasonably short. For multi-line subjects that we squish
into a single line, we just "pre-folded" the data in
pp_title_line by adding a newline and indentation.
There were two problems. One is that, although rare,
single-line messages can actually be longer than the
recommended line-length limits. The second is that the
pre-folding interacted badly with rfc2047 encoding, leading
to malformed headers.
Instead, let's stop pre-folding the subject lines, and just
fold everything based on length in add_rfc2047, whether
it is encoded or not.
Signed-off-by: Jeff King <peff@xxxxxxxx>
---
Three things to note:
1. We call strbuf_add_wrapped_bytes for the non-encoded case. This
nicely wraps on word and multi-character boundaries. But it will
never do a "hard" wrap if there are no word boundaries, and it
probably should at the 998-character mark which rfc2822 specifies
as a hard limit.
I don't know how much we care. For something like that you'd have
to be maliciously trying to create a bogus patch. If you're mailing
it, you could just create the bogus mail by hand. If you're trying
to buffer overflow somebody's "format-patch | am" script, it won't
do anything, as mailinfo does not have a limit on line length.
2. For the non-quoted case, technically we want to indent less on the
first line than we do on subsequent lines (to account for "Subject:
[PATCH]"). strbuf_add_wrapped_bytes doesn't support that notion. We
could add it, but it probably doesn't matter. We just end up
wrapping the subsequent lines a little tighter than we need to.
3. I used RFC2822's SHOULD value of 78 characters as a line length.
That's probably unnecessarily conservative. In theory wrapping
shouldn't make a difference to the data, but maybe people who
hand-edit the result would prefer not to see wrapping? I dunno. In
that case, we could set it to something higher like 120, which
would still wrap the really ridiculous cases.
pretty.c | 32 +++++++++++++----
t/t4014-format-patch.sh | 84 +++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 108 insertions(+), 8 deletions(-)
diff --git a/pretty.c b/pretty.c
index 8549934..0e167f4 100644
--- a/pretty.c
+++ b/pretty.c
@@ -216,7 +216,15 @@ static int is_rfc2047_special(char ch)
static void add_rfc2047(struct strbuf *sb, const char *line, int len,
const char *encoding)
{
- int i, last;
+ static const int max_length = 78; /* per rfc2822 */
+ int i;
+ int line_len;
+
+ /* How many bytes are already used on the current line? */
+ for (i = sb->len - 1; i >= 0; i--)
+ if (sb->buf[i] == '\n')
+ break;
+ line_len = sb->len - (i+1);
for (i = 0; i < len; i++) {
int ch = line[i];
@@ -225,14 +233,21 @@ static void add_rfc2047(struct strbuf *sb, const char *line, int len,
if ((i + 1 < len) && (ch == '=' && line[i+1] == '?'))
goto needquote;
}
- strbuf_add(sb, line, len);
+ strbuf_add_wrapped_bytes(sb, line, len, 0, 1, max_length - line_len);
return;
needquote:
strbuf_grow(sb, len * 3 + strlen(encoding) + 100);
strbuf_addf(sb, "=?%s?q?", encoding);
- for (i = last = 0; i < len; i++) {
+ line_len += strlen(encoding) + 5; /* 5 for =??q? */
+ for (i = 0; i < len; i++) {
unsigned ch = line[i] & 0xFF;
+
+ if (line_len >= max_length - 2) {
+ strbuf_addf(sb, "?=\n =?%s?q?", encoding);
+ line_len = strlen(encoding) + 5 + 1; /* =??q? plus SP */
+ }
+
/*
* We encode ' ' using '=20' even though rfc2047
* allows using '_' for readability. Unfortunately,
@@ -240,12 +255,14 @@ needquote:
* leave the underscore in place.
*/
if (is_rfc2047_special(ch) || ch == ' ') {
- strbuf_add(sb, line + last, i - last);
strbuf_addf(sb, "=%02X", ch);
- last = i + 1;
+ line_len += 3;
+ }
+ else {
+ strbuf_addch(sb, ch);
+ line_len++;
}
}
- strbuf_add(sb, line + last, len - last);
strbuf_addstr(sb, "?=");
}
@@ -1106,11 +1123,10 @@ void pp_title_line(enum cmit_fmt fmt,
const char *encoding,
int need_8bit_cte)
{
- const char *line_separator = (fmt == CMIT_FMT_EMAIL) ? "\n " : " ";
struct strbuf title;
strbuf_init(&title, 80);
- *msg_p = format_subject(&title, *msg_p, line_separator);
+ *msg_p = format_subject(&title, *msg_p, " ");
strbuf_grow(sb, title.len + 1024);
if (subject) {
diff --git a/t/t4014-format-patch.sh b/t/t4014-format-patch.sh
index 027c13d..9c66367 100755
--- a/t/t4014-format-patch.sh
+++ b/t/t4014-format-patch.sh
@@ -709,4 +709,88 @@ test_expect_success TTY 'format-patch --stdout paginates' '
test_path_is_missing .git/pager_used
'
+test_expect_success 'format-patch handles multi-line subjects' '
+ rm -rf patches/ &&
+ echo content >>file &&
+ for i in one two three; do echo $i; done >msg &&
+ git add file &&
+ git commit -F msg &&
+ git format-patch -o patches -1 &&
+ grep ^Subject: patches/0001-one.patch >actual &&
+ echo "Subject: [PATCH] one two three" >expect &&
+ test_cmp expect actual
+'
+
+test_expect_success 'format-patch handles multi-line encoded subjects' '
+ rm -rf patches/ &&
+ echo content >>file &&
+ for i in en tvà tre; do echo $i; done >msg &&
+ git add file &&
+ git commit -F msg &&
+ git format-patch -o patches -1 &&
+ grep ^Subject: patches/0001-en.patch >actual &&
+ echo "Subject: [PATCH] =?UTF-8?q?en=20tv=C3=A5=20tre?=" >expect &&
+ test_cmp expect actual
+'
+
+M8="foo bar "
+M64=$M8$M8$M8$M8$M8$M8$M8$M8
+M512=$M64$M64$M64$M64$M64$M64$M64$M64
+cat >expect <<'EOF'
+Subject: [PATCH] foo bar foo bar foo bar foo bar foo bar foo bar foo bar foo
+ bar foo bar foo bar foo bar foo bar foo bar foo bar foo bar
+ foo bar foo bar foo bar foo bar foo bar foo bar foo bar foo
+ bar foo bar foo bar foo bar foo bar foo bar foo bar foo bar
+ foo bar foo bar foo bar foo bar foo bar foo bar foo bar foo
+ bar foo bar foo bar foo bar foo bar foo bar foo bar foo bar
+ foo bar foo bar foo bar foo bar foo bar foo bar foo bar foo
+ bar foo bar foo bar foo bar foo bar foo bar foo bar foo bar
+ foo bar foo bar foo bar foo bar
+EOF
+test_expect_success 'format-patch wraps extremely long headers (ascii)' '
+ echo content >>file &&
+ git add file &&
+ git commit -m "$M512" &&
+ git format-patch --stdout -1 >patch &&
+ sed -n "/^Subject/p; /^ /p; /^$/q" <patch >subject &&
+ test_cmp expect subject
+'
+
+M8="fÃÃ bar "
+M64=$M8$M8$M8$M8$M8$M8$M8$M8
+M512=$M64$M64$M64$M64$M64$M64$M64$M64
+cat >expect <<'EOF'
+Subject: [PATCH] =?UTF-8?q?f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6=C3=B6=20bar=20f=C3=B6?=
+ =?UTF-8?q?=C3=B6=20bar=20f=C3=B6=C3=B6=20bar?=
+EOF
+test_expect_success 'format-patch wraps extremely long headers (rfc2047)' '
+ rm -rf patches/ &&
+ echo content >>file &&
+ git add file &&
+ git commit -m "$M512" &&
+ git format-patch --stdout -1 >patch &&
+ sed -n "/^Subject/p; /^ /p; /^$/q" <patch >subject &&
+ test_cmp expect subject
+'
+
test_done
--
1.7.2.5.15.gfdd1c
--
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