git-am: add --directory=<dir> option

Thanks to a200337 (git-am: propagate -C<n>, -p<n> options as well,
2008-12-04) and commits around it, "git am" is equipped to correctly
propagate the command line flags such as -C/-p/-whitespace across a patch
failure and restart.

It is trivial to support --directory option now, resurrecting previous
attempts by Kevin and Simon.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-am.txt

@@ -11,7 +11,7 @@ SYNOPSIS
 [verse]
 'git am' [--signoff] [--keep] [--utf8 | --no-utf8]
 	 [--3way] [--interactive]
-         [--whitespace=<option>] [-C<n>] [-p<n>]
+	 [--whitespace=<option>] [-C<n>] [-p<n>] [--directory=<dir>]
 	 [<mbox> | <Maildir>...]
 'git am' (--skip | --resolved | --abort)
 
@@ -60,12 +60,9 @@ default.   You could use `--no-utf8` to override this.
 	available locally.
 
 --whitespace=<option>::
-	This flag is passed to the 'git-apply' (see linkgit:git-apply[1])
-	program that applies
-	the patch.
-
 -C<n>::
 -p<n>::
+--directory=<dir>::
 	These flags are passed to the 'git-apply' (see linkgit:git-apply[1])
 	program that applies
 	the patch.

git-am.sh

@@ -16,6 +16,7 @@ s,signoff       add a Signed-off-by line to the commit message
 u,utf8          recode into utf8 (default)
 k,keep          pass -k flag to git-mailinfo
 whitespace=     pass it through git-apply
+directory=      pass it through git-apply
 C=              pass it through git-apply
 p=              pass it through git-apply
 resolvemsg=     override error message when patch failure occurs
@@ -33,6 +34,14 @@ cd_to_toplevel
 git var GIT_COMMITTER_IDENT >/dev/null ||
 	die "You need to set your committer info first"
 
+sq () {
+	for sqarg
+	do
+		printf "%s" "$sqarg" |
+		sed -e 's/'\''/'\''\'\'''\''/g' -e 's/.*/ '\''&'\''/'
+	done
+}
+
 stop_here () {
     echo "$1" >"$dotest/next"
     exit 1
@@ -155,10 +164,10 @@ do
 		;;
 	--resolvemsg)
 		shift; resolvemsg=$1 ;;
-	--whitespace)
-		git_apply_opt="$git_apply_opt $1=$2"; shift ;;
+	--whitespace|--directory)
+		git_apply_opt="$git_apply_opt $(sq "$1=$2")"; shift ;;
 	-C|-p)
-		git_apply_opt="$git_apply_opt $1$2"; shift ;;
+		git_apply_opt="$git_apply_opt $(sq "$1$2")"; shift ;;
 	--)
 		shift; break ;;
 	*)
@@ -459,7 +468,7 @@ do
 
 	case "$resolved" in
 	'')
-		git apply $git_apply_opt --index "$dotest/patch"
+		eval 'git apply '"$git_apply_opt"' --index "$dotest/patch"'
 		apply_status=$?
 		;;
 	t)

t/t4252-am-options.sh

@@ -50,4 +50,12 @@ test_expect_success 'interrupted am -C1 -p2' '
 	grep "^Three$" file-2
 '
 
+test_expect_success 'interrupted am --directory="frotz nitfol"' '
+	rm -rf .git/rebase-apply &&
+	git reset --hard initial &&
+	test_must_fail git am --directory="frotz nitfol" "$tm"/am-test-5-? &&
+	git am --skip &&
+	grep One "frotz nitfol/file-5"
+'
+
 test_done

t/t4252/am-test-5-1

@@ -0,0 +1,20 @@
+From: A U Thor <au.thor@example.com>
+Date: Thu Dec 4 16:00:00 2008 -0800
+Subject: Six
+
+Applying this patch with --directory='frotz nitfol' should fail
+
+diff --git i/junk/file-2 w/junk/file-2
+index 06e567b..b6f3a16 100644
+--- i/junk/file-2
++++ w/junk/file-2
+@@ -1,7 +1,7 @@
+ One
+ 2
+-3
++Three
+ 4
+ 5
+-6
++Six
+ 7

t/t4252/am-test-5-2

@@ -0,0 +1,15 @@
+From: A U Thor <au.thor@example.com>
+Date: Thu Dec 4 16:00:00 2008 -0800
+Subject: Six
+
+Applying this patch with --directory='frotz nitfol' should succeed
+
+diff --git i/file-5 w/file-5
+new file mode 100644
+index 000000..1d6ed9f
+--- /dev/null
++++ w/file-5
+@@ -0,0 +1,3 @@
++One
++two
++three