[PATCH v3 5/6] mailinfo: allow stripping quoted CR without warning

["Đoàn Trần Công Danh" <congdanhqx@gmail.com>]

In previous changes, we've turned on warning for quoted CR in base64 or
quoted-printable email messages. Some projects see those quoted CR a lot,
they know that it happens most of the time, and they find it's desirable
to always strip those CR.

Those projects in question usually fall back to use other tools to handle
patches when receive such patches.

Let's help those projects handle those patches by stripping those
excessive CR.

Signed-off-by: Đoàn Trần Công Danh <congdanhqx@gmail.com>
---
 Documentation/git-mailinfo.txt | 1 +
 mailinfo.c                     | 7 +++++++
 mailinfo.h                     | 1 +
 t/t5100-mailinfo.sh            | 4 ++++
 4 files changed, 13 insertions(+)

diff --git a/Documentation/git-mailinfo.txt b/Documentation/git-mailinfo.txt
index 824947a070..3fcfd965fd 100644
--- a/Documentation/git-mailinfo.txt
+++ b/Documentation/git-mailinfo.txt
@@ -102,6 +102,7 @@ The valid actions are:
 *	`nowarn`: Git will do nothing when such a CRLF is found.
 *	`warn`: Git will issue a warning for each message if such a CRLF is
 	found.
+*	`strip`: Git will convert those CRLF to LF.
 --
 +
 The default action could be set by configuration option `mailinfo.quotedCR`.
diff --git a/mailinfo.c b/mailinfo.c
index c57eed25a5..5cddcdc8ae 100644
--- a/mailinfo.c
+++ b/mailinfo.c
@@ -998,6 +998,11 @@ static void handle_filter_flowed(struct mailinfo *mi, struct strbuf *line,
 		    line->buf[len - 2] == '\r' &&
 		    line->buf[len - 1] == '\n') {
 			mi->have_quoted_cr = 1;
+			if (mi->quoted_cr == quoted_cr_strip) {
+				strbuf_setlen(line, len - 2);
+				strbuf_addch(line, '\n');
+				len--;
+			}
 		}
 		handle_filter(mi, line);
 		return;
@@ -1227,6 +1232,8 @@ int mailinfo_parse_quoted_cr_action(const char *actionstr, int *action)
 		*action = quoted_cr_nowarn;
 	else if (!strcmp(actionstr, "warn"))
 		*action = quoted_cr_warn;
+	else if (!strcmp(actionstr, "strip"))
+		*action = quoted_cr_strip;
 	else
 		return -1;
 	return 0;
diff --git a/mailinfo.h b/mailinfo.h
index 768d06ac2a..2ddf8be90f 100644
--- a/mailinfo.h
+++ b/mailinfo.h
@@ -8,6 +8,7 @@
 enum quoted_cr_action {
 	quoted_cr_nowarn,
 	quoted_cr_warn,
+	quoted_cr_strip,
 };
 
 struct mailinfo {
diff --git a/t/t5100-mailinfo.sh b/t/t5100-mailinfo.sh
index 51e8690fbd..06807f3852 100755
--- a/t/t5100-mailinfo.sh
+++ b/t/t5100-mailinfo.sh
@@ -242,6 +242,10 @@ test_expect_success 'mailinfo handle CR in base64 encoded email' '
 	check_quoted_cr_mail &&
 	grep "quoted CR detected" quoted-cr-err &&
 	check_quoted_cr_mail --quoted-cr=nowarn &&
+	test_must_be_empty quoted-cr-err &&
+	sed "s/%%//" "$DATA/quoted-cr-msg" >expect-cr-msg &&
+	sed "s/%%//" "$DATA/quoted-cr-patch" >expect-cr-patch &&
+	check_quoted_cr_mail --quoted-cr=strip &&
 	test_must_be_empty quoted-cr-err
 '
 
-- 
2.31.1.448.g9c2f8508d1