log,diff-tree: add --combined-all-paths option

The combined diff format for merges will only list one filename, even if
rename or copy detection is active.  For example, with raw format one
might see:

  ::100644 100644 100644 fabadb8 cc95eb0 4866510 MM	describe.c
  ::100755 100755 100755 52b7a2d 6d1ac04 d2ac7d7 RM	bar.sh
  ::100644 100644 100644 e07d6c5 9042e82 ee91881 RR	phooey.c

This doesn't let us know what the original name of bar.sh was in the
first parent, and doesn't let us know what either of the original names
of phooey.c were in either of the parents.  In contrast, for non-merge
commits, raw format does provide original filenames (and a rename score
to boot).  In order to also provide original filenames for merge
commits, add a --combined-all-paths option (which must be used with
either -c or --cc, and is likely only useful with rename or copy
detection active) so that we can print tab-separated filenames when
renames are involved.  This transforms the above output to:

  ::100644 100644 100644 fabadb8 cc95eb0 4866510 MM	desc.c	desc.c	desc.c
  ::100755 100755 100755 52b7a2d 6d1ac04 d2ac7d7 RM	foo.sh	bar.sh	bar.sh
  ::100644 100644 100644 e07d6c5 9042e82 ee91881 RR	fooey.c	fuey.c	phooey.c

Further, in patch format, this changes the from/to headers so that
instead of just having one "from" header, we get one for each parent.
For example, instead of having

  --- a/phooey.c
  +++ b/phooey.c

we would see

  --- a/fooey.c
  --- a/fuey.c
  +++ b/phooey.c

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 88 insertions, 0 deletions

diff --git a/t/t4038-diff-combined.sh b/t/t4038-diff-combined.sh
index e2824d3..07b49f6 100755
--- a/t/t4038-diff-combined.sh
+++ b/t/t4038-diff-combined.sh
@@ -435,4 +435,92 @@ test_expect_success 'combine diff gets tree sorting right' '
 	test_cmp expect actual
 '
 
+test_expect_success 'setup for --combined-all-paths' '
+	git branch side1c &&
+	git branch side2c &&
+	git checkout side1c &&
+	test_seq 1 10 >filename-side1c &&
+	git add filename-side1c &&
+	git commit -m with &&
+	git checkout side2c &&
+	test_seq 1 9 >filename-side2c &&
+	echo ten >>filename-side2c &&
+	git add filename-side2c &&
+	git commit -m iam &&
+	git checkout -b mergery side1c &&
+	git merge --no-commit side2c &&
+	git rm filename-side1c &&
+	echo eleven >>filename-side2c &&
+	git mv filename-side2c filename-merged &&
+	git add filename-merged &&
+	git commit
+'
+
+test_expect_success '--combined-all-paths and --raw' '
+	cat <<-\EOF >expect &&
+	::100644 100644 100644 f00c965d8307308469e537302baa73048488f162 088bd5d92c2a8e0203ca8e7e4c2a5c692f6ae3f7 333b9c62519f285e1854830ade0fe1ef1d40ee1b RR	filename-side1c	filename-side2c	filename-merged
+	EOF
+	git diff-tree -c -M --raw --combined-all-paths HEAD >actual.tmp &&
+	sed 1d <actual.tmp >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--combined-all-paths and --cc' '
+	cat <<-\EOF >expect &&
+	--- a/filename-side1c
+	--- a/filename-side2c
+	+++ b/filename-merged
+	EOF
+	git diff-tree --cc -M --combined-all-paths HEAD >actual.tmp &&
+	grep ^[-+][-+][-+] <actual.tmp >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success FUNNYNAMES 'setup for --combined-all-paths with funny names' '
+	git branch side1d &&
+	git branch side2d &&
+	git checkout side1d &&
+	test_seq 1 10 >$(printf "file\twith\ttabs") &&
+	git add file* &&
+	git commit -m with &&
+	git checkout side2d &&
+	test_seq 1 9 >$(printf "i\tam\ttabbed") &&
+	echo ten >>$(printf "i\tam\ttabbed") &&
+	git add *tabbed &&
+	git commit -m iam &&
+	git checkout -b funny-names-mergery side1d &&
+	git merge --no-commit side2d &&
+	git rm *tabs &&
+	echo eleven >>$(printf "i\tam\ttabbed") &&
+	git mv "$(printf "i\tam\ttabbed")" "$(printf "fickle\tnaming")" &&
+	git add fickle* &&
+	git commit
+'
+
+test_expect_success FUNNYNAMES '--combined-all-paths and --raw and funny names' '
+	cat <<-\EOF >expect &&
+	::100644 100644 100644 f00c965d8307308469e537302baa73048488f162 088bd5d92c2a8e0203ca8e7e4c2a5c692f6ae3f7 333b9c62519f285e1854830ade0fe1ef1d40ee1b RR	"file\twith\ttabs"	"i\tam\ttabbed"	"fickle\tnaming"
+	EOF
+	git diff-tree -c -M --raw --combined-all-paths HEAD >actual.tmp &&
+	sed 1d <actual.tmp >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success FUNNYNAMES '--combined-all-paths and --raw -and -z and funny names' '
+	printf "aaf8087c3cbd4db8e185a2d074cf27c53cfb75d7\0::100644 100644 100644 f00c965d8307308469e537302baa73048488f162 088bd5d92c2a8e0203ca8e7e4c2a5c692f6ae3f7 333b9c62519f285e1854830ade0fe1ef1d40ee1b RR\0file\twith\ttabs\0i\tam\ttabbed\0fickle\tnaming\0" >expect &&
+	git diff-tree -c -M --raw --combined-all-paths -z HEAD >actual &&
+	test_cmp -a expect actual
+'
+
+test_expect_success FUNNYNAMES '--combined-all-paths and --cc and funny names' '
+	cat <<-\EOF >expect &&
+	--- "a/file\twith\ttabs"
+	--- "a/i\tam\ttabbed"
+	+++ "b/fickle\tnaming"
+	EOF
+	git diff-tree --cc -M --combined-all-paths HEAD >actual.tmp &&
+	grep ^[-+][-+][-+] <actual.tmp >actual &&
+	test_cmp expect actual
+'
+
 test_done