merge-ort: capture and print ll-merge warnings in our preferred fashion

Instead of immediately printing ll-merge warnings to stderr, we save
them in our output strbuf.  Besides allowing us to move these warnings
to a special file for --remerge-diff, this has two other benefits for
regular merges done by merge-ort:

  * The deferral of messages ensures we can print all messages about
    any given path together (merge-recursive was known to sometimes
    intersperse messages about other paths, particularly when renames
    were involved).

  * The deferral of messages means we can avoid printing spurious
    conflict messages when we just end up aborting due to local user
    modifications in the way.  (In contrast to merge-recursive.c which
    prematurely checks for local modifications in the way via
    unpack_trees() and gets the check wrong both in terms of false
    positives and false negatives relative to renames, merge-ort does
    not perform the local modifications in the way check until the
    checkout() step after the full merge has been computed.)

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

1 files changed, 3 insertions, 2 deletions

diff --git a/merge-ort.c b/merge-ort.c
index c24da2ba3c..a18f47e23c 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -1788,8 +1788,9 @@ static int merge_3way(struct merge_options *opt,
 				&src1, name1, &src2, name2,
 				&opt->priv->attr_index, &ll_opts);
 	if (merge_status == LL_MERGE_BINARY_CONFLICT)
-		warning("Cannot merge binary files: %s (%s vs. %s)",
-			path, name1, name2);
+		path_msg(opt, path, 0,
+			 "warning: Cannot merge binary files: %s (%s vs. %s)",
+			 path, name1, name2);
 
 	free(base);
 	free(name1);