[PATCH 2/2] git-merge-file: do not add LF at EOF while applying unrelated change

[Max Kirillov <max@max630.net>]

If 'current-file' does not contain LF at EOF, and change between
'base-file' and 'other-file' does not change any line close to EOF, the
3-way merge should not add LF to EOF.  This is what 'diff3 -m' does, and
seems to be a reasonable expectation.

The change which introduced the behavior is cd1d61c44f and was about
union merge. The union merges are tested in the t6026-merge-attr, and
merge-file in general are tested in t6023-merge-file. Add tests
"merge conflicting with --.." there, to verify that the fix does not
break anything.

Also add tests "merge without conflict (missing LF at EOF, away from
change in the other file)" and "merge does not add LF away of change",
to demonstrate the changed behavior.

Signed-off-by: Max Kirillov <max@max630.net>
---
 t/t6023-merge-file.sh | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++
 xdiff/xmerge.c        |  4 ++--
 2 files changed, 68 insertions(+), 2 deletions(-)

diff --git a/t/t6023-merge-file.sh b/t/t6023-merge-file.sh
index 6da921c..21d1b85 100755
--- a/t/t6023-merge-file.sh
+++ b/t/t6023-merge-file.sh
@@ -83,6 +83,23 @@ test_expect_failure "merge without conflict (missing LF at EOF)" \
 test_expect_failure "merge result added missing LF" \
 	"test_cmp test.txt test2.txt"
 
+cp new4.txt test3.txt
+test_expect_success "merge without conflict (missing LF at EOF, away from change in the other file)" \
+	"git merge-file --quiet test3.txt new2.txt new3.txt"
+
+cat > expect.txt << EOF
+DOMINUS regit me,
+et nihil mihi deerit.
+In loco pascuae ibi me collocavit,
+super aquam refectionis educavit me;
+animam meam convertit,
+deduxit me super semitas jusitiae,
+EOF
+printf "propter nomen suum." >> expect.txt
+
+test_expect_success "merge does not add LF away of change" \
+	"test_cmp test3.txt expect.txt"
+
 cp test.txt backup.txt
 test_expect_success "merge with conflicts" \
 	"test_must_fail git merge-file test.txt orig.txt new3.txt"
@@ -107,6 +124,55 @@ EOF
 test_expect_success "expected conflict markers" "test_cmp test.txt expect.txt"
 
 cp backup.txt test.txt
+
+cat > expect.txt << EOF
+Dominus regit me, et nihil mihi deerit.
+In loco pascuae ibi me collocavit,
+super aquam refectionis educavit me;
+animam meam convertit,
+deduxit me super semitas jusitiae,
+propter nomen suum.
+Nam et si ambulavero in medio umbrae mortis,
+non timebo mala, quoniam tu mecum es:
+virga tua et baculus tuus ipsa me consolata sunt.
+EOF
+test_expect_success "merge conflicting with --ours" \
+	"git merge-file --ours test.txt orig.txt new3.txt && test_cmp test.txt expect.txt"
+cp backup.txt test.txt
+
+cat > expect.txt << EOF
+DOMINUS regit me,
+et nihil mihi deerit.
+In loco pascuae ibi me collocavit,
+super aquam refectionis educavit me;
+animam meam convertit,
+deduxit me super semitas jusitiae,
+propter nomen suum.
+Nam et si ambulavero in medio umbrae mortis,
+non timebo mala, quoniam tu mecum es:
+virga tua et baculus tuus ipsa me consolata sunt.
+EOF
+test_expect_success "merge conflicting with --theirs" \
+	"git merge-file --theirs test.txt orig.txt new3.txt && test_cmp test.txt expect.txt"
+cp backup.txt test.txt
+
+cat > expect.txt << EOF
+Dominus regit me, et nihil mihi deerit.
+DOMINUS regit me,
+et nihil mihi deerit.
+In loco pascuae ibi me collocavit,
+super aquam refectionis educavit me;
+animam meam convertit,
+deduxit me super semitas jusitiae,
+propter nomen suum.
+Nam et si ambulavero in medio umbrae mortis,
+non timebo mala, quoniam tu mecum es:
+virga tua et baculus tuus ipsa me consolata sunt.
+EOF
+test_expect_success "merge conflicting with --union" \
+	"git merge-file --union test.txt orig.txt new3.txt && test_cmp test.txt expect.txt"
+cp backup.txt test.txt
+
 test_expect_success "merge with conflicts, using -L" \
 	"test_must_fail git merge-file -L 1 -L 2 test.txt orig.txt new3.txt"
 
diff --git a/xdiff/xmerge.c b/xdiff/xmerge.c
index 9e13b25..5f7a95a 100644
--- a/xdiff/xmerge.c
+++ b/xdiff/xmerge.c
@@ -245,11 +245,11 @@ static int xdl_fill_merge_buffer(xdfenv_t *xe1, const char *name1,
 					      dest ? dest + size : NULL);
 			/* Postimage from side #1 */
 			if (m->mode & 1)
-				size += xdl_recs_copy(xe1, m->i1, m->chg1, 1,
+				size += xdl_recs_copy(xe1, m->i1, m->chg1, 0,
 						      dest ? dest + size : NULL);
 			/* Postimage from side #2 */
 			if (m->mode & 2)
-				size += xdl_recs_copy(xe2, m->i2, m->chg2, 1,
+				size += xdl_recs_copy(xe2, m->i2, m->chg2, 0,
 						      dest ? dest + size : NULL);
 		} else
 			continue;
-- 
2.0.0.526.g5318336