add--interactive: allow user to choose mode update

When using the 'p'atch command, instead of just throwing out any mode
change, present it to the user in the same way that we show hunks.

This way, the mode change can be staged independently from the changes
to the contents.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

2 files changed, 44 insertions, 1 deletions

diff --git a/git-add--interactive.perl b/git-add--interactive.perl
index 5cdda29c5..903953e68 100755
--- a/git-add--interactive.perl
+++ b/git-add--interactive.perl
@@ -814,6 +814,36 @@ sub patch_update_file {
 	for (@{$head->{DISPLAY}}) {
 		print;
 	}
+
+	if (@{$mode->{TEXT}}) {
+		while (1) {
+			print @{$mode->{DISPLAY}};
+			print colored $prompt_color,
+				"Stage mode change [y/n/a/d/?]? ";
+			my $line = <STDIN>;
+			if ($line =~ /^y/i) {
+				$mode->{USE} = 1;
+				last;
+			}
+			elsif ($line =~ /^n/i) {
+				$mode->{USE} = 0;
+				last;
+			}
+			elsif ($line =~ /^a/i) {
+				$_->{USE} = 1 foreach ($mode, @hunk);
+				last;
+			}
+			elsif ($line =~ /^d/i) {
+				$_->{USE} = 0 foreach ($mode, @hunk);
+				last;
+			}
+			else {
+				help_patch_cmd('');
+				next;
+			}
+		}
+	}
+
 	$num = scalar @hunk;
 	$ix = 0;
 
@@ -936,6 +966,9 @@ sub patch_update_file {
 
 	my $n_lofs = 0;
 	my @result = ();
+	if ($mode->{USE}) {
+		push @result, @{$mode->{TEXT}};
+	}
 	for (@hunk) {
 		my $text = $_->{TEXT};
 		my ($o_ofs, $o_cnt, $n_ofs, $n_cnt) =
diff --git a/t/t3701-add-interactive.sh b/t/t3701-add-interactive.sh
index d920d06d5..f15be93e7 100755
--- a/t/t3701-add-interactive.sh
+++ b/t/t3701-add-interactive.sh
@@ -70,9 +70,19 @@ test_expect_success 'patch does not affect mode' '
 	git reset --hard &&
 	echo content >>file &&
 	chmod +x file &&
-	printf "y\\n" | git add -p &&
+	printf "n\\ny\\n" | git add -p &&
 	git show :file | grep content &&
 	git diff file | grep "new mode"
 '
 
+test_expect_success 'stage mode but not hunk' '
+	git reset --hard &&
+	echo content >>file &&
+	chmod +x file &&
+	printf "y\\nn\\n" | git add -p &&
+	git diff --cached file | grep "new mode" &&
+	git diff          file | grep "+content"
+'
+
+
 test_done