From 22cb3835b90f80b2de2bc8f5ff3a9e8eed5ff40a Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Mon, 12 Nov 2018 12:54:49 -0800
Subject: apply --recount: allow "no-op hunks"

When editing patches e.g. in `git add -e`, it is quite common that a
hunk ends up having no -/+ lines, i.e. it is now supposed to do nothing.

This use case was broken by ad6e8ed37bc1 (apply: reject a hunk that does
not do anything, 2015-06-01) with the good intention of catching a very
real, different issue in hand-edited patches.

So let's use the `--recount` option as the tell-tale whether the user
would actually be okay with no-op hunks.

Add a test case to make sure that this use case does not regress again.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Reviewed-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/apply.c b/apply.c
index e485fbc..5fb8ecf 100644
--- a/apply.c
+++ b/apply.c
@@ -1747,7 +1747,7 @@ static int parse_fragment(struct apply_state *state,
 	}
 	if (oldlines || newlines)
 		return -1;
-	if (!deleted && !added)
+	if (!patch->recount && !deleted && !added)
 		return -1;
 
 	fragment->leading = leading;
diff --git a/t/t4136-apply-check.sh b/t/t4136-apply-check.sh
index 6d92872..4c3f264 100755
--- a/t/t4136-apply-check.sh
+++ b/t/t4136-apply-check.sh
@@ -29,6 +29,18 @@ test_expect_success 'apply exits non-zero with no-op patch' '
 	test_must_fail git apply --check input
 '
 
+test_expect_success '`apply --recount` allows no-op patch' '
+	echo 1 >1 &&
+	git apply --recount --check <<-\EOF
+	diff --get a/1 b/1
+	index 6696ea4..606eddd 100644
+	--- a/1
+	+++ b/1
+	@@ -1,1 +1,1 @@
+	 1
+	EOF
+'
+
 test_expect_success 'invalid combination: create and copy' '
 	test_must_fail git apply --check - <<-\EOF
 	diff --git a/1 b/2
-- 
cgit v0.10.2-6-g49f6