git-am: implement --reject option passed to git-apply

With --reject, git-am simply passes the --reject option to git-apply and thus
allows people to work with reject files if they so prefer.

Signed-off-by: martin f. krafft <madduck@madduck.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-am.txt

@@ -12,6 +12,7 @@ SYNOPSIS
 'git am' [--signoff] [--keep] [--utf8 | --no-utf8]
 	 [--3way] [--interactive]
 	 [--whitespace=<option>] [-C<n>] [-p<n>] [--directory=<dir>]
+	 [--reject]
 	 [<mbox> | <Maildir>...]
 'git am' (--skip | --resolved | --abort)
 
@@ -63,6 +64,7 @@ default.   You could use `--no-utf8` to override this.
 -C<n>::
 -p<n>::
 --directory=<dir>::
+--reject::
 	These flags are passed to the 'git-apply' (see linkgit:git-apply[1])
 	program that applies
 	the patch.

git-am.sh

@@ -19,6 +19,7 @@ whitespace=     pass it through git-apply
 directory=      pass it through git-apply
 C=              pass it through git-apply
 p=              pass it through git-apply
+reject          pass it through git-apply
 resolvemsg=     override error message when patch failure occurs
 r,resolved      to be used after a patch failure
 skip            skip the current patch
@@ -168,6 +169,8 @@ do
 		git_apply_opt="$git_apply_opt $(sq "$1=$2")"; shift ;;
 	-C|-p)
 		git_apply_opt="$git_apply_opt $(sq "$1$2")"; shift ;;
+	--reject)
+		git_apply_opt="$git_apply_opt $1" ;;
 	--)
 		shift; break ;;
 	*)

t/t4252-am-options.sh

@@ -1,6 +1,6 @@
 #!/bin/sh
 
-test_description='git am not losing options'
+test_description='git am with options and not losing them'
 . ./test-lib.sh
 
 tm="$TEST_DIRECTORY/t4252"
@@ -66,4 +66,13 @@ test_expect_success 'apply to a funny path' '
 	test -f "$with_sq/file-5"
 '
 
+test_expect_success 'am --reject' '
+	rm -rf .git/rebase-apply &&
+	git reset --hard initial &&
+	test_must_fail git am --reject "$tm"/am-test-6-1 &&
+	grep "@@ -1,3 +1,3 @@" file-2.rej &&
+	test_must_fail git diff-files --exit-code --quiet file-2 &&
+	grep "[-]-reject" .git/rebase-apply/apply-opt
+'
+
 test_done

t/t4252/am-test-6-1

@@ -0,0 +1,21 @@
+From: A U Thor <au.thor@example.com>
+Date: Thu Dec 4 16:00:00 2008 -0800
+Subject: Huh
+
+Should fail and leave rejects
+
+diff --git i/file-2 w/file-2
+index 06e567b..b6f3a16 100644
+--- i/file-2
++++ w/file-2
+@@ -1,3 +1,3 @@
+-0
++One
+ 2
+ 3
+@@ -4,4 +4,4 @@
+ 4
+ 5
+-6
++Six
+ 7