Re: [PATCH] git-svn: Add a svn-remote.<name>.pushurl config key

[Jeff King <peff@peff.net>]

On Fri, Apr 08, 2011 at 03:25:09PM -0700, Junio C Hamano wrote:

> Jeff King <peff@peff.net> writes:
> 
> > I disagree. Format-patch claims to make an mbox, so it should make one
> > that is valid.
> 
> OK.  That makes sense (even though I think it would make cutting and
> pasting somewhat awkward).

Cutting and pasting is already potentially awkward, because we
rfc2047-quote in format-patch, too. But we can still get away without
quoting at all in regular "git log". The "Author:" lines, while
rfc822-looking do not have to be real header lines, and we know that
everything before the <> must be the name.

So I think this is the patch we want:

-- >8 --
Subject: [PATCH] pretty: quote rfc822 specials in email addresses

If somebody has a name that includes an rfc822 special, we
will output it literally in the "From:" header. This is
usually OK, but certain characters (like ".") are supposed
to be enclosed in double-quotes in a mail header.

In practice, whether this matters may depend on your MUA.
Some MUAs will happily take in:

   From: Foo B. Bar <author@example.com>

without quotes, and properly quote the "." when they send
the actual mail.  Others may not, or may screw up harder
things like:

  From: Foo "The Baz" Bar <author@example.com>

For example, mutt will strip the quotes, thinking they are
actual syntactic rfc822 quotes.

So let's quote properly, and then (if necessary) we still
apply rfc2047 encoding on top of that, which should make all
MUAs happy.

Signed-off-by: Jeff King <peff@peff.net>
---
 pretty.c                |   61 ++++++++++++++++++++++++++++++++++++++++++++++-
 t/t4014-format-patch.sh |   42 ++++++++++++++++++++++++++++++++
 2 files changed, 102 insertions(+), 1 deletions(-)

diff --git a/pretty.c b/pretty.c
index e1d8a8f..8345485 100644
--- a/pretty.c
+++ b/pretty.c
@@ -208,6 +208,58 @@ int has_non_ascii(const char *s)
 	return 0;
 }
 
+static int is_rfc822_special(char ch)
+{
+	switch (ch) {
+	case '(':
+	case ')':
+	case '<':
+	case '>':
+	case '[':
+	case ']':
+	case ':':
+	case ';':
+	case '@':
+	case ',':
+	case '.':
+	case '"':
+	case '\\':
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+static int has_rfc822_specials(const char *s, int len)
+{
+	int i;
+	for (i = 0; i < len; i++)
+		if (is_rfc822_special(s[i]))
+			return 1;
+	return 0;
+}
+
+static void add_rfc822_quoted(struct strbuf *out, const char *s, int len)
+{
+	int i;
+
+	/* just a guess, we may have to also backslash-quote */
+	strbuf_grow(out, len + 2);
+
+	strbuf_addch(out, '"');
+	for (i = 0; i < len; i++) {
+		switch (s[i]) {
+		case '"':
+		case '\\':
+			strbuf_addch(out, '\\');
+			/* fall through */
+		default:
+			strbuf_addch(out, s[i]);
+		}
+	}
+	strbuf_addch(out, '"');
+}
+
 static int is_rfc2047_special(char ch)
 {
 	return (non_ascii(ch) || (ch == '=') || (ch == '?') || (ch == '_'));
@@ -293,7 +345,14 @@ void pp_user_info(const char *what, enum cmit_fmt fmt, struct strbuf *sb,
 			name_tail--;
 		display_name_length = name_tail - line;
 		strbuf_addstr(sb, "From: ");
-		add_rfc2047(sb, line, display_name_length, encoding);
+		if (has_rfc822_specials(line, display_name_length)) {
+			struct strbuf quoted = STRBUF_INIT;
+			add_rfc822_quoted(&quoted, line, display_name_length);
+			add_rfc2047(sb, quoted.buf, quoted.len, encoding);
+			strbuf_release(&quoted);
+		}
+		else
+			add_rfc2047(sb, line, display_name_length, encoding);
 		strbuf_add(sb, name_tail, namelen - display_name_length);
 		strbuf_addch(sb, '\n');
 	} else {
diff --git a/t/t4014-format-patch.sh b/t/t4014-format-patch.sh
index c3cdb52..dd406c4 100755
--- a/t/t4014-format-patch.sh
+++ b/t/t4014-format-patch.sh
@@ -793,4 +793,46 @@ test_expect_success 'format-patch wraps extremely long headers (rfc2047)' '
 	test_cmp expect subject
 '
 
+check_author() {
+	echo content >>file &&
+	git add file &&
+	GIT_AUTHOR_NAME=$1 git commit -m author-check &&
+	git format-patch --stdout -1 >patch &&
+	grep ^From: patch >actual &&
+	test_cmp expect actual
+}
+
+cat >expect <<'EOF'
+From: "Foo B. Bar" <author@example.com>
+EOF
+test_expect_success 'format-patch quotes dot in headers' '
+	check_author "Foo B. Bar"
+'
+
+cat >expect <<'EOF'
+From: "Foo \"The Baz\" Bar" <author@example.com>
+EOF
+test_expect_success 'format-patch quotes double-quote in headers' '
+	check_author "Foo \"The Baz\" Bar"
+'
+
+cat >expect <<'EOF'
+From: =?UTF-8?q?"F=C3=B6o=20B.=20Bar"?= <author@example.com>
+EOF
+test_expect_success 'rfc2047-encoded headers also double-quote 822 specials' '
+	check_author "Föo B. Bar"
+'
+
+cat >expect <<'EOF'
+Subject: header with . in it
+EOF
+test_expect_success 'subject lines do not have 822 atom-quoting' '
+	echo content >>file &&
+	git add file &&
+	git commit -m "header with . in it" &&
+	git format-patch -k -1 --stdout >patch &&
+	grep ^Subject: patch >actual &&
+	test_cmp expect actual
+'
+
 test_done
-- 
1.7.5.rc1.24.gcff72