[PATCH 2/5] am: teach StGit 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 StGit 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     |  5 +++--
 t/t4150-am.sh | 10 ++++++++++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/git-am.sh b/git-am.sh
index 761befb..83f2ea6 100755
--- a/git-am.sh
+++ b/git-am.sh
@@ -297,6 +297,7 @@ split_patches () {
 		;;
 	stgit)
 		this=0
+		test 0 -eq "$#" && set -- -
 		for stgit in "$@"
 		do
 			this=$(expr "$this" + 1)
@@ -305,7 +306,7 @@ split_patches () {
 			# not starting with Author, From or Date is the
 			# subject, and the body starts with the next nonempty
 			# line not starting with Author, From or Date
-			@@PERL@@ -ne 'BEGIN { $subject = 0 }
+			cat "$stgit" | @@PERL@@ -ne 'BEGIN { $subject = 0 }
 				if ($subject > 1) { print ; }
 				elsif (/^\s+$/) { next ; }
 				elsif (/^Author:/) { s/Author/From/ ; print ;}
@@ -318,7 +319,7 @@ split_patches () {
 					print "Subject: ", $_ ;
 					$subject = 1;
 				}
-			' < "$stgit" > "$dotest/$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 0ead529..51962e4 100755
--- a/t/t4150-am.sh
+++ b/t/t4150-am.sh
@@ -209,6 +209,16 @@ test_expect_success 'am applies stgit patch' '
 	test_cmp_rev second^ HEAD^
 '
 
+test_expect_success 'am --patch-format=stgit applies stgit patch' '
+	rm -fr .git/rebase-apply &&
+	git checkout -f first &&
+	git am --patch-format=stgit <patch1-stgit.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