[PATCH] threeway_merge: if file will not be touched, leave it alone

If the merge base _and_ the to-be merged brach have a certain file, but
HEAD has not, do not complain if that file exists anyway. It will not be
overwritten.

Signed-off-by: Johannes Schindelin <redacted>

---

	On Fri, 20 Oct 2006, Junio C Hamano wrote:

	> While we are talking about merge-recursive, I could use some
	> help from somebody familiar with merge-recursive to complete the
	> read-tree changes Linus mentioned early this month.
	>
	> The issue is that we would want to remove one verify_absent()
	> call in unpack-tree.c:threeway_merge().  When read-tree decides
	> to leave higher stages around, we do not want it to check if the
	> merge could clobber a working tree file, because having an
	> unrelated file at the same path in the working tree sometimes is
	> and sometimes is not a conflict, depending on the outcome of the
	> merge, and that part of the code does not _know_ the outcome
	> yet.

	How about this? It passes the testsuite, and I tested it with the 
	test case you did, and with the same test case with recursive 
	merge.

 unpack-trees.c |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/unpack-trees.c b/unpack-trees.c
index 3ac0289..b4994c4 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c

@@ -658,10 +658,9 @@ int threeway_merge(struct cache_entry **
 	 * up-to-date to avoid the files getting overwritten with
 	 * conflict resolution files.
 	 */
-	if (index) {
+	if (index)
 		verify_uptodate(index, o);
-	}
-	else if (path)
+	else if (no_anc_exists)
 		verify_absent(path, "overwritten", o);
 
 	o->nontrivial_merge = 1;

-- 
1.4.3.1.ga3de1-dirty