[PATCH] merge-tree: sometimes, d/f conflict is not an issue

From

Johannes Schindelin <johannes.schindelin@gmx.de>

Date

Jul 8, 2007, 00:52 UTC

Message-ID

<Pine.LNX.4.64.0707080148370.4093@racer.site>

In-Reply-To

<20070625071819.8091.qmail@5e4088a43a10fd.315fe32.mid.smarden.org>

Noticed by Rémi Vanicat, reported to the Git list by Gerrit Pape.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---

	The only peculiar result is that you can have an entry at
	stage 0 for one path, and stages 1 and 3 for another path
	where the first path is a prefix.

	This can happen now, when you have deleted a directory
	since the branching point, and put a file in the same place, but
	the other side has changed files in that directory.

	This change is reflected in the change to t3030.

	I have no idea if the change is the best there is, but after
	spending some hours trying to get my head around what is written
	in Documentation/technical/trivial-merge.txt, and what is in
	the function threeway_merge(), and still not understanding most of 
	it, there is not much more that I can do.

	Funny note at the side: when I finally got to Gerrit's email again
	today, gmane said _almost_ that it was 3 weeks, 3 days, 3 hours
	and 3 minutes ago...

 t/t3030-merge-recursive.sh |    2 +-
 t/t3502-cherry-pick.sh     |   31 +++++++++++++++++++++++++++++++
 unpack-trees.c             |   14 ++++++++++++++
 3 files changed, 46 insertions(+), 1 deletions(-)
 create mode 100755 t/t3502-cherry-pick.sh

diff --git a/t/t3030-merge-recursive.sh b/t/t3030-merge-recursive.sh
index 607f57f..d413af1 100755
--- a/t/t3030-merge-recursive.sh
+++ b/t/t3030-merge-recursive.sh
@@ -450,7 +450,7 @@ test_expect_success 'merge-recursive d/f conflict result' '
 		echo "100644 $o1 0	a"
 		echo "100644 $o0 0	b"
 		echo "100644 $o0 0	c"
-		echo "100644 $o6 2	d"
+		echo "100644 $o6 0	d"
 		echo "100644 $o0 1	d/e"
 		echo "100644 $o1 3	d/e"
 	) >expected &&
diff --git a/t/t3502-cherry-pick.sh b/t/t3502-cherry-pick.sh
new file mode 100755
index 0000000..da3d26e
--- /dev/null
+++ b/t/t3502-cherry-pick.sh
@@ -0,0 +1,31 @@
+#!/bin/sh
+
+test_description='test cherry-pick'
+
+. ./test-lib.sh
+
+test_expect_success setup '
+	echo foo > file &&
+	ln -s dangling link &&
+	git add file link &&
+	test_tick &&
+	git commit -m foo &&
+	git checkout -b branch &&
+	git rm link &&
+	test_tick &&
+	git commit -m "remove link" &&
+	mkdir link &&
+	echo bar > link/file &&
+	git add link/file &&
+	test_tick &&
+	git commit -m "add dir" &&
+	echo bar > file &&
+	git commit -m "change file" file &&
+	git checkout master
+'
+
+test_expect_success 'cherry-pick ignores unrelated dir/symlink conflict' '
+	git cherry-pick branch
+'
+
+test_done
diff --git a/unpack-trees.c b/unpack-trees.c
index cac2411..080b016 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -643,6 +643,20 @@ int threeway_merge(struct cache_entry **stages,
 	index = stages[0];
 	head = stages[o->head_idx];
 
+	/*
+	 * Special case: do not care about a dir/file conflict, when
+	 * the entries have not been touched.
+	 * IOW if the ancestors are identical to the remote, and the
+	 * index is the same as head, just take head.
+	 */
+	if (head && same(index, head)) {
+		for (i = 1; i < o->head_idx; i++)
+			if (!same(stages[i], remote))
+				break;
+		if (i == o->head_idx)
+			return merged_entry(head, index, o);
+	}
+
 	if (head == o->df_conflict_entry) {
 		df_conflict_head = 1;
 		head = NULL;

-- 
1.5.3.rc0.2712.g125b7f