diff --git a/Documentation/git-am.txt b/Documentation/git-am.txt
index decd8ae1227..8714dfcb762 100644
--- a/Documentation/git-am.txt
+++ b/Documentation/git-am.txt
@@ -15,6 +15,7 @@ SYNOPSIS
 	 [--whitespace=<option>] [-C<n>] [-p<n>] [--directory=<dir>]
 	 [--exclude=<path>] [--include=<path>] [--reject] [-q | --quiet]
 	 [--[no-]scissors] [-S[<keyid>]] [--patch-format=<format>]
+	 [--quoted-cr=<action>]
 	 [(<mbox> | <Maildir>)...]
 'git am' (--continue | --skip | --abort | --quit | --show-current-patch[=(diff|raw)])
 
@@ -59,6 +60,9 @@ OPTIONS
 --no-scissors::
 	Ignore scissors lines (see linkgit:git-mailinfo[1]).
 
+--quoted-cr=<action>::
+	This flag will be passed down to 'git mailinfo' (see linkgit:git-mailinfo[1]).
+
 -m::
 --message-id::
 	Pass the `-m` flag to 'git mailinfo' (see linkgit:git-mailinfo[1]),
diff --git a/Documentation/git-mailinfo.txt b/Documentation/git-mailinfo.txt
index d343f040f53..3fcfd965fde 100644
--- a/Documentation/git-mailinfo.txt
+++ b/Documentation/git-mailinfo.txt
@@ -9,7 +9,9 @@ git-mailinfo - Extracts patch and authorship from a single e-mail message
 SYNOPSIS
 --------
 [verse]
-'git mailinfo' [-k|-b] [-u | --encoding=<encoding> | -n] [--[no-]scissors] <msg> <patch>
+'git mailinfo' [-k|-b] [-u | --encoding=<encoding> | -n]
+	       [--[no-]scissors] [--quoted-cr=<action>]
+	       <msg> <patch>
 
 
 DESCRIPTION
@@ -89,6 +91,23 @@ This can be enabled by default with the configuration option mailinfo.scissors.
 --no-scissors::
 	Ignore scissors lines. Useful for overriding mailinfo.scissors settings.
 
+--quoted-cr=<action>::
+	Action when processes email messages sent with base64 or
+	quoted-printable encoding, and the decoded lines end with a CRLF
+	instead of a simple LF.
++
+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`.
+If no such configuration option has been set, `warn` will be used.
+
 <msg>::
 	The commit log message extracted from e-mail, usually
 	except the title line which comes from e-mail Subject.
diff --git a/builtin/am.c b/builtin/am.c
index 8355e3566ff..0b2d886c81b 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -116,6 +116,7 @@ struct am_state {
 	int keep; /* enum keep_type */
 	int message_id;
 	int scissors; /* enum scissors_type */
+	int quoted_cr; /* enum quoted_cr_action */
 	struct strvec git_apply_opts;
 	const char *resolvemsg;
 	int committer_date_is_author_date;
@@ -145,6 +146,7 @@ static void am_state_init(struct am_state *state)
 	git_config_get_bool("am.messageid", &state->message_id);
 
 	state->scissors = SCISSORS_UNSET;
+	state->quoted_cr = quoted_cr_unset;
 
 	strvec_init(&state->git_apply_opts);
 
@@ -165,6 +167,16 @@ static void am_state_release(struct am_state *state)
 	strvec_clear(&state->git_apply_opts);
 }
 
+static int am_option_parse_quoted_cr(const struct option *opt,
+				     const char *arg, int unset)
+{
+	BUG_ON_OPT_NEG(unset);
+
+	if (mailinfo_parse_quoted_cr_action(arg, opt->value) != 0)
+		return error(_("bad action '%s' for '%s'"), arg, "--quoted-cr");
+	return 0;
+}
+
 /**
  * Returns path relative to the am_state directory.
  */
@@ -397,6 +409,12 @@ static void am_load(struct am_state *state)
 	else
 		state->scissors = SCISSORS_UNSET;
 
+	read_state_file(&sb, state, "quoted-cr", 1);
+	if (!*sb.buf)
+		state->quoted_cr = quoted_cr_unset;
+	else if (mailinfo_parse_quoted_cr_action(sb.buf, &state->quoted_cr) != 0)
+		die(_("could not parse %s"), am_path(state, "quoted-cr"));
+
 	read_state_file(&sb, state, "apply-opt", 1);
 	strvec_clear(&state->git_apply_opts);
 	if (sq_dequote_to_strvec(sb.buf, &state->git_apply_opts) < 0)
@@ -1002,6 +1020,24 @@ static void am_setup(struct am_state *state, enum patch_format patch_format,
 	}
 	write_state_text(state, "scissors", str);
 
+	switch (state->quoted_cr) {
+	case quoted_cr_unset:
+		str = "";
+		break;
+	case quoted_cr_nowarn:
+		str = "nowarn";
+		break;
+	case quoted_cr_warn:
+		str = "warn";
+		break;
+	case quoted_cr_strip:
+		str = "strip";
+		break;
+	default:
+		BUG("invalid value for state->quoted_cr");
+	}
+	write_state_text(state, "quoted-cr", str);
+
 	sq_quote_argv(&sb, state->git_apply_opts.v);
 	write_state_text(state, "apply-opt", sb.buf);
 
@@ -1162,6 +1198,18 @@ static int parse_mail(struct am_state *state, const char *mail)
 		BUG("invalid value for state->scissors");
 	}
 
+	switch (state->quoted_cr) {
+	case quoted_cr_unset:
+		break;
+	case quoted_cr_nowarn:
+	case quoted_cr_warn:
+	case quoted_cr_strip:
+		mi.quoted_cr = state->quoted_cr;
+		break;
+	default:
+		BUG("invalid value for state->quoted_cr");
+	}
+
 	mi.input = xfopen(mail, "r");
 	mi.output = xfopen(am_path(state, "info"), "w");
 	if (mailinfo(&mi, am_path(state, "msg"), am_path(state, "patch")))
@@ -2242,6 +2290,9 @@ int cmd_am(int argc, const char **argv, const char *prefix)
 			0, PARSE_OPT_NONEG),
 		OPT_BOOL('c', "scissors", &state.scissors,
 			N_("strip everything before a scissors line")),
+		OPT_CALLBACK_F(0, "quoted-cr", &state.quoted_cr, N_("action"),
+			       N_("pass it through git-mailinfo"),
+			       PARSE_OPT_NONEG, am_option_parse_quoted_cr),
 		OPT_PASSTHRU_ARGV(0, "whitespace", &state.git_apply_opts, N_("action"),
 			N_("pass it through git-apply"),
 			0),
diff --git a/builtin/mailinfo.c b/builtin/mailinfo.c
index cfb667a594c..01d16ef9e5a 100644
--- a/builtin/mailinfo.c
+++ b/builtin/mailinfo.c
@@ -7,54 +7,103 @@
 #include "utf8.h"
 #include "strbuf.h"
 #include "mailinfo.h"
+#include "parse-options.h"
 
-static const char mailinfo_usage[] =
-	"git mailinfo [-k | -b] [-m | --message-id] [-u | --encoding=<encoding> | -n] [--scissors | --no-scissors] <msg> <patch> < mail >info";
+static const char * const mailinfo_usage[] = {
+	/* TRANSLATORS: keep <> in "<" mail ">" info. */
+	N_("git mailinfo [<options>] <msg> <patch> < mail >info"),
+	NULL,
+};
+
+struct metainfo_charset
+{
+	enum {
+		CHARSET_DEFAULT,
+		CHARSET_NO_REENCODE,
+		CHARSET_EXPLICIT,
+	} policy;
+	const char *charset;
+};
+
+static int parse_opt_explicit_encoding(const struct option *opt,
+				       const char *arg, int unset)
+{
+	struct metainfo_charset *meta_charset = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+
+	meta_charset->policy = CHARSET_EXPLICIT;
+	meta_charset->charset = arg;
+
+	return 0;
+}
+
+static int parse_opt_quoted_cr(const struct option *opt, const char *arg, int unset)
+{
+	BUG_ON_OPT_NEG(unset);
+
+	if (mailinfo_parse_quoted_cr_action(arg, opt->value) != 0)
+		return error(_("bad action '%s' for '%s'"), arg, "--quoted-cr");
+	return 0;
+}
 
 int cmd_mailinfo(int argc, const char **argv, const char *prefix)
 {
-	const char *def_charset;
+	struct metainfo_charset meta_charset;
 	struct mailinfo mi;
 	int status;
 	char *msgfile, *patchfile;
 
+	struct option options[] = {
+		OPT_BOOL('k', NULL, &mi.keep_subject, N_("keep subject")),
+		OPT_BOOL('b', NULL, &mi.keep_non_patch_brackets_in_subject,
+			 N_("keep non patch brackets in subject")),
+		OPT_BOOL('m', "message-id", &mi.add_message_id,
+			 N_("copy Message-ID to the end of commit message")),
+		OPT_SET_INT_F('u', NULL, &meta_charset.policy,
+			      N_("re-code metadata to i18n.commitEncoding"),
+			      CHARSET_DEFAULT, PARSE_OPT_NONEG),
+		OPT_SET_INT_F('n', NULL, &meta_charset.policy,
+			      N_("disable charset re-coding of metadata"),
+			      CHARSET_NO_REENCODE, PARSE_OPT_NONEG),
+		OPT_CALLBACK_F(0, "encoding", &meta_charset, N_("encoding"),
+			       N_("re-code metadata to this encoding"),
+			       PARSE_OPT_NONEG, parse_opt_explicit_encoding),
+		OPT_BOOL(0, "scissors", &mi.use_scissors, N_("use scissors")),
+		OPT_CALLBACK_F(0, "quoted-cr", &mi.quoted_cr, N_("<action>"),
+			       N_("action when quoted CR is found"),
+			       PARSE_OPT_NONEG, parse_opt_quoted_cr),
+		OPT_HIDDEN_BOOL(0, "inbody-headers", &mi.use_inbody_headers,
+			 N_("use headers in message's body")),
+		OPT_END()
+	};
+
 	setup_mailinfo(&mi);
+	meta_charset.policy = CHARSET_DEFAULT;
 
-	def_charset = get_commit_output_encoding();
-	mi.metainfo_charset = def_charset;
+	argc = parse_options(argc, argv, prefix, options, mailinfo_usage, 0);
 
-	while (1 < argc && argv[1][0] == '-') {
-		if (!strcmp(argv[1], "-k"))
-			mi.keep_subject = 1;
-		else if (!strcmp(argv[1], "-b"))
-			mi.keep_non_patch_brackets_in_subject = 1;
-		else if (!strcmp(argv[1], "-m") || !strcmp(argv[1], "--message-id"))
-			mi.add_message_id = 1;
-		else if (!strcmp(argv[1], "-u"))
-			mi.metainfo_charset = def_charset;
-		else if (!strcmp(argv[1], "-n"))
-			mi.metainfo_charset = NULL;
-		else if (starts_with(argv[1], "--encoding="))
-			mi.metainfo_charset = argv[1] + 11;
-		else if (!strcmp(argv[1], "--scissors"))
-			mi.use_scissors = 1;
-		else if (!strcmp(argv[1], "--no-scissors"))
-			mi.use_scissors = 0;
-		else if (!strcmp(argv[1], "--no-inbody-headers"))
-			mi.use_inbody_headers = 0;
-		else
-			usage(mailinfo_usage);
-		argc--; argv++;
+	if (argc != 2)
+		usage_with_options(mailinfo_usage, options);
+
+	switch (meta_charset.policy) {
+	case CHARSET_DEFAULT:
+		mi.metainfo_charset = get_commit_output_encoding();
+		break;
+	case CHARSET_NO_REENCODE:
+		mi.metainfo_charset = NULL;
+		break;
+	case CHARSET_EXPLICIT:
+		break;
+	default:
+		BUG("invalid meta_charset.policy");
 	}
 
-	if (argc != 3)
-		usage(mailinfo_usage);
-
 	mi.input = stdin;
 	mi.output = stdout;
 
-	msgfile = prefix_filename(prefix, argv[1]);
-	patchfile = prefix_filename(prefix, argv[2]);
+	msgfile = prefix_filename(prefix, argv[0]);
+	patchfile = prefix_filename(prefix, argv[1]);
 
 	status = !!mailinfo(&mi, msgfile, patchfile);
 	clear_mailinfo(&mi);
diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 5722ef07aac..3c5739b9059 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -1333,6 +1333,7 @@ __git_whitespacelist="nowarn warn error error-all fix"
 __git_patchformat="mbox stgit stgit-series hg mboxrd"
 __git_showcurrentpatch="diff raw"
 __git_am_inprogress_options="--skip --continue --resolved --abort --quit --show-current-patch"
+__git_quoted_cr="nowarn warn strip"
 
 _git_am ()
 {
@@ -1354,6 +1355,10 @@ _git_am ()
 		__gitcomp "$__git_showcurrentpatch" "" "${cur##--show-current-patch=}"
 		return
 		;;
+	--quoted-cr=*)
+		__gitcomp "$__git_quoted_cr" "" "${cur##--quoted-cr=}"
+		return
+		;;
 	--*)
 		__gitcomp_builtin am "" \
 			"$__git_am_inprogress_options"
diff --git a/mailinfo.c b/mailinfo.c
index 95ce191f385..ccc6beb27e2 100644
--- a/mailinfo.c
+++ b/mailinfo.c
@@ -994,6 +994,16 @@ static void handle_filter_flowed(struct mailinfo *mi, struct strbuf *line,
 	const char *rest;
 
 	if (!mi->format_flowed) {
+		if (len >= 2 &&
+		    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;
 	}
@@ -1033,6 +1043,13 @@ static void handle_filter_flowed(struct mailinfo *mi, struct strbuf *line,
 	handle_filter(mi, line);
 }
 
+static void summarize_quoted_cr(struct mailinfo *mi)
+{
+	if (mi->have_quoted_cr &&
+	    mi->quoted_cr == quoted_cr_warn)
+		warning(_("quoted CRLF detected"));
+}
+
 static void handle_body(struct mailinfo *mi, struct strbuf *line)
 {
 	struct strbuf prev = STRBUF_INIT;
@@ -1051,6 +1068,8 @@ static void handle_body(struct mailinfo *mi, struct strbuf *line)
 				handle_filter(mi, &prev);
 				strbuf_reset(&prev);
 			}
+			summarize_quoted_cr(mi);
+			mi->have_quoted_cr = 0;
 			if (!handle_boundary(mi, line))
 				goto handle_body_out;
 		}
@@ -1100,6 +1119,7 @@ static void handle_body(struct mailinfo *mi, struct strbuf *line)
 
 	if (prev.len)
 		handle_filter(mi, &prev);
+	summarize_quoted_cr(mi);
 
 	flush_inbody_header_accum(mi);
 
@@ -1206,6 +1226,19 @@ int mailinfo(struct mailinfo *mi, const char *msg, const char *patch)
 	return mi->input_error;
 }
 
+int mailinfo_parse_quoted_cr_action(const char *actionstr, int *action)
+{
+	if (!strcmp(actionstr, "nowarn"))
+		*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;
+}
+
 static int git_mailinfo_config(const char *var, const char *value, void *mi_)
 {
 	struct mailinfo *mi = mi_;
@@ -1216,6 +1249,11 @@ static int git_mailinfo_config(const char *var, const char *value, void *mi_)
 		mi->use_scissors = git_config_bool(var, value);
 		return 0;
 	}
+	if (!strcmp(var, "mailinfo.quotedcr")) {
+		if (mailinfo_parse_quoted_cr_action(value, &mi->quoted_cr) != 0)
+			return error(_("bad action '%s' for '%s'"), value, var);
+		return 0;
+	}
 	/* perhaps others here */
 	return 0;
 }
@@ -1228,6 +1266,7 @@ void setup_mailinfo(struct mailinfo *mi)
 	strbuf_init(&mi->charset, 0);
 	strbuf_init(&mi->log_message, 0);
 	strbuf_init(&mi->inbody_header_accum, 0);
+	mi->quoted_cr = quoted_cr_warn;
 	mi->header_stage = 1;
 	mi->use_inbody_headers = 1;
 	mi->content_top = mi->content;
diff --git a/mailinfo.h b/mailinfo.h
index 79b1d6774ec..f2ffd0349e8 100644
--- a/mailinfo.h
+++ b/mailinfo.h
@@ -5,6 +5,13 @@
 
 #define MAX_BOUNDARIES 5
 
+enum quoted_cr_action {
+	quoted_cr_unset = -1,
+	quoted_cr_nowarn,
+	quoted_cr_warn,
+	quoted_cr_strip,
+};
+
 struct mailinfo {
 	FILE *input;
 	FILE *output;
@@ -14,6 +21,7 @@ struct mailinfo {
 	struct strbuf email;
 	int keep_subject;
 	int keep_non_patch_brackets_in_subject;
+	int quoted_cr; /* enum quoted_cr_action */
 	int add_message_id;
 	int use_scissors;
 	int use_inbody_headers;
@@ -24,6 +32,7 @@ struct mailinfo {
 	struct strbuf charset;
 	unsigned int format_flowed:1;
 	unsigned int delsp:1;
+	unsigned int have_quoted_cr:1;
 	char *message_id;
 	enum  {
 		TE_DONTCARE, TE_QP, TE_BASE64
@@ -39,6 +48,7 @@ struct mailinfo {
 	int input_error;
 };
 
+int mailinfo_parse_quoted_cr_action(const char *actionstr, int *action);
 void setup_mailinfo(struct mailinfo *);
 int mailinfo(struct mailinfo *, const char *msg, const char *patch);
 void clear_mailinfo(struct mailinfo *);
diff --git a/t/t4258-am-quoted-cr.sh b/t/t4258-am-quoted-cr.sh
new file mode 100755
index 00000000000..fb5071f9140
--- /dev/null
+++ b/t/t4258-am-quoted-cr.sh
@@ -0,0 +1,37 @@
+#!/bin/sh
+
+test_description='test am --quoted-cr=<action>'
+
+. ./test-lib.sh
+
+DATA="$TEST_DIRECTORY/t4258"
+
+test_expect_success 'setup' '
+	test_write_lines one two three >text &&
+	test_commit one text &&
+	test_write_lines one owt three >text &&
+	test_commit two text
+'
+
+test_expect_success 'am warn if quoted-cr is found' '
+	git reset --hard one &&
+	test_must_fail git am "$DATA/mbox" 2>err &&
+	grep "quoted CRLF detected" err
+'
+
+test_expect_success 'am --quoted-cr=strip' '
+	test_might_fail git am --abort &&
+	git reset --hard one &&
+	git am --quoted-cr=strip "$DATA/mbox" &&
+	git diff --exit-code HEAD two
+'
+
+test_expect_success 'am with config mailinfo.quotecr=strip' '
+	test_might_fail git am --abort &&
+	git reset --hard one &&
+	test_config mailinfo.quotedCr strip &&
+	git am "$DATA/mbox" &&
+	git diff --exit-code HEAD two
+'
+
+test_done
diff --git a/t/t4258/mbox b/t/t4258/mbox
new file mode 100644
index 00000000000..c62819f3d25
--- /dev/null
+++ b/t/t4258/mbox
@@ -0,0 +1,12 @@
+From: A U Thor <mail@example.com>
+To: list@example.org
+Subject: [PATCH v2] sample
+Date: Mon,  3 Aug 2020 22:40:55 +0700
+Message-Id: <msg-id@example.com>
+Content-Type: text/plain; charset="utf-8"
+Content-Transfer-Encoding: base64
+
+VGhpcyBpcyBjb21taXQgbWVzc2FnZS4NCi0tLQ0KIHRleHQgfCAyICstDQogMSBmaWxlIGNoYW5n
+ZWQsIDEgaW5zZXJ0aW9uKCspLCAxIGRlbGV0aW9uKC0pDQoNCmRpZmYgLS1naXQgYS90ZXh0IGIv
+dGV4dA0KaW5kZXggNTYyNmFiZi4uZjcxOWVmZCAxMDA2NDQNCi0tLSBhL3RleHQNCisrKyBiL3Rl
+eHQNCkBAIC0xICsxIEBADQotb25lDQordHdvDQotLSANCjIuMzEuMQoK
diff --git a/t/t5100-mailinfo.sh b/t/t5100-mailinfo.sh
index 147e616533c..141b29f0319 100755
--- a/t/t5100-mailinfo.sh
+++ b/t/t5100-mailinfo.sh
@@ -228,4 +228,44 @@ test_expect_success 'mailinfo handles unusual header whitespace' '
 	test_cmp expect actual
 '
 
+check_quoted_cr_mail () {
+	mail="$1" && shift &&
+	git mailinfo -u "$@" "$mail.msg" "$mail.patch" \
+		<"$mail" >"$mail.info" 2>"$mail.err" &&
+	test_cmp "$mail-expected.msg" "$mail.msg" &&
+	test_cmp "$mail-expected.patch" "$mail.patch" &&
+	test_cmp "$DATA/quoted-cr-info" "$mail.info"
+}
+
+test_expect_success 'split base64 email with quoted-cr' '
+	mkdir quoted-cr &&
+	git mailsplit -oquoted-cr "$DATA/quoted-cr.mbox" >quoted-cr/last &&
+	test $(cat quoted-cr/last) = 2
+'
+
+test_expect_success 'mailinfo warn CR in base64 encoded email' '
+	sed -e "s/%%$//" -e "s/%%/$(printf \\015)/g" "$DATA/quoted-cr-msg" \
+		>quoted-cr/0001-expected.msg &&
+	sed "s/%%/$(printf \\015)/g" "$DATA/quoted-cr-msg" \
+		>quoted-cr/0002-expected.msg &&
+	sed -e "s/%%$//" -e "s/%%/$(printf \\015)/g" "$DATA/quoted-cr-patch" \
+		>quoted-cr/0001-expected.patch &&
+	sed "s/%%/$(printf \\015)/g" "$DATA/quoted-cr-patch" \
+		>quoted-cr/0002-expected.patch &&
+	check_quoted_cr_mail quoted-cr/0001 &&
+	test_must_be_empty quoted-cr/0001.err &&
+	check_quoted_cr_mail quoted-cr/0002 &&
+	grep "quoted CRLF detected" quoted-cr/0002.err &&
+	check_quoted_cr_mail quoted-cr/0001 --quoted-cr=nowarn &&
+	test_must_be_empty quoted-cr/0001.err &&
+	check_quoted_cr_mail quoted-cr/0002 --quoted-cr=nowarn &&
+	test_must_be_empty quoted-cr/0002.err &&
+	cp quoted-cr/0001-expected.msg quoted-cr/0002-expected.msg &&
+	cp quoted-cr/0001-expected.patch quoted-cr/0002-expected.patch &&
+	check_quoted_cr_mail quoted-cr/0001 --quoted-cr=strip &&
+	test_must_be_empty quoted-cr/0001.err &&
+	check_quoted_cr_mail quoted-cr/0002 --quoted-cr=strip &&
+	test_must_be_empty quoted-cr/0002.err
+'
+
 test_done
diff --git a/t/t5100/quoted-cr-info b/t/t5100/quoted-cr-info
new file mode 100644
index 00000000000..dab2228b70a
--- /dev/null
+++ b/t/t5100/quoted-cr-info
@@ -0,0 +1,5 @@
+Author: A U Thor
+Email: mail@example.com
+Subject: sample
+Date: Mon, 3 Aug 2020 22:40:55 +0700
+
diff --git a/t/t5100/quoted-cr-msg b/t/t5100/quoted-cr-msg
new file mode 100644
index 00000000000..89b05a07844
--- /dev/null
+++ b/t/t5100/quoted-cr-msg
@@ -0,0 +1,2 @@
+On different distro, %%pytest is suffixed with different patterns.%%
+%%
diff --git a/t/t5100/quoted-cr-patch b/t/t5100/quoted-cr-patch
new file mode 100644
index 00000000000..65b13eeef70
--- /dev/null
+++ b/t/t5100/quoted-cr-patch
@@ -0,0 +1,22 @@
+---%%
+ configure | 2 +-%%
+ 1 file changed, 1 insertion(+), 1 deletion(-)%%
+%%
+diff --git a/configure b/configure%%
+index db3538b3..f7c1c095 100755%%
+--- a/configure%%
++++ b/configure%%
+@@ -814,7 +814,7 @@ if [ $have_python3 -eq 1 ]; then%%
+     printf "%%Checking for python3 pytest (>= 3.0)... "%%
+     conf=$(mktemp)%%
+     printf "[pytest]\nminversion=3.0\n" > $conf%%
+-    if pytest-3 -c $conf --version >/dev/null 2>&1; then%%
++    if "$python" -m pytest -c $conf --version >/dev/null 2>&1; then%%
+         printf "Yes.\n"%%
+         have_python3_pytest=1%%
+     else%%
+-- %%
+2.28.0%%
+_______________________________________________
+example mailing list -- list@example.org
+To unsubscribe send an email to list-leave@example.org
diff --git a/t/t5100/quoted-cr.mbox b/t/t5100/quoted-cr.mbox
new file mode 100644
index 00000000000..909021bb7a8
--- /dev/null
+++ b/t/t5100/quoted-cr.mbox
@@ -0,0 +1,47 @@
+From nobody Mon Sep 17 00:00:00 2001
+From: A U Thor <mail@example.com>
+To: list@example.org
+Subject: [PATCH v2] sample
+Date: Mon,  3 Aug 2020 22:40:55 +0700
+Message-Id: <msg-id@example.com>
+Content-Type: text/plain; charset="utf-8"
+Content-Transfer-Encoding: base64
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+From nobody Mon Sep 17 00:00:00 2001
+From: A U Thor <mail@example.com>
+To: list@example.org
+Subject: [PATCH v2] sample
+Date: Mon,  3 Aug 2020 22:40:55 +0700
+Message-Id: <msg-id2@example.com>
+Content-Type: text/plain; charset="utf-8"
+Content-Transfer-Encoding: base64
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