[PATCH 5/5] am: teach mercurial patch parser how to read from stdin

[Paul Tan <pyokagan@gmail.com>]

git-mailsplit, which splits mbox patches, will read the patch from stdin
when the filename is "-" or there are no files listed on the
command-line.

To be consistent with this behavior, teach the mercurial patch parser to
read from stdin if the filename is "-" or no files are listed on the
command-line.

Based-on-patch-by: Chris Packham <judge.packham@gmail.com>
Signed-off-by: Paul Tan <pyokagan@gmail.com>
---
 git-am.sh     |  4 +++-
 t/t4150-am.sh | 10 ++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/git-am.sh b/git-am.sh
index d97da85..0a40d46 100755
--- a/git-am.sh
+++ b/git-am.sh
@@ -327,6 +327,7 @@ split_patches () {
 		;;
 	hg)
 		this=0
+		test 0 -eq "$#" && set -- -
 		for hg in "$@"
 		do
 			this=$(( $this + 1 ))
@@ -338,6 +339,7 @@ split_patches () {
 			# Since we cannot guarantee that the commit message is in
 			# git-friendly format, we put no Subject: line and just consume
 			# all of the message as the body
+			cat "$hg" |
 			LANG=C LC_ALL=C @@PERL@@ -M'POSIX qw(strftime)' -ne 'BEGIN { $subject = 0 }
 				if ($subject) { print ; }
 				elsif (/^\# User /) { s/\# User/From:/ ; print ; }
@@ -353,7 +355,7 @@ split_patches () {
 					print "\n", $_ ;
 					$subject = 1;
 				}
-			' <"$hg" >"$dotest/$msgnum" || clean_abort
+			' >"$dotest/$msgnum" || clean_abort
 		done
 		echo "$this" >"$dotest/last"
 		this=
diff --git a/t/t4150-am.sh b/t/t4150-am.sh
index 4beb4b3..3ebafd9 100755
--- a/t/t4150-am.sh
+++ b/t/t4150-am.sh
@@ -259,6 +259,16 @@ test_expect_success 'am applies hg patch' '
 	test_cmp_rev second^ HEAD^
 '
 
+test_expect_success 'am --patch-format=hg applies hg patch' '
+	rm -fr .git/rebase-apply &&
+	git checkout -f first &&
+	git am --patch-format=hg <patch1-hg.eml &&
+	test_path_is_missing .git/rebase-apply &&
+	git diff --exit-code second &&
+	test_cmp_rev second HEAD &&
+	test_cmp_rev second^ HEAD^
+'
+
 test_expect_success 'setup: new author and committer' '
 	GIT_AUTHOR_NAME="Another Thor" &&
 	GIT_AUTHOR_EMAIL="a.thor@example.com" &&
-- 
2.1.4