Merge branch 'en/merge-rename-rename-worktree-fix'

When a binary file gets modified and renamed on both sides of history
to different locations, both files would be written to the working
tree but both would have the contents from "ours".  This has been
corrected so that the path from each side gets their original content.

* en/merge-rename-rename-worktree-fix:
  merge-recursive: fix rename/rename(1to2) for working tree with a binary

Author: gitster

merge-recursive.c

@@ -1750,6 +1750,18 @@ static int handle_rename_rename_1to2(struct merge_options *opt,
 			return -1;
 	}
 
+	if (!mfi.clean && mfi.blob.mode == a->mode &&
+	    oideq(&mfi.blob.oid, &a->oid)) {
+		/*
+		 * Getting here means we were attempting to merge a binary
+		 * blob.  Since we can't merge binaries, the merge algorithm
+		 * just takes one side.  But we don't want to copy the
+		 * contents of one side to both paths; we'd rather use the
+		 * original content at the given path for each path.
+		 */
+		oidcpy(&mfi.blob.oid, &b->oid);
+		mfi.blob.mode = b->mode;
+	}
 	add = &ci->ren2->dst_entry->stages[flip_stage(3)];
 	if (is_valid(add)) {
 		add->path = mfi.blob.path = b->path;

t/t6042-merge-rename-corner-cases.sh

@@ -1379,4 +1379,59 @@ test_expect_success 'check nested conflicts from rename/rename(2to1)' '
 	)
 '
 
+# Testcase rename/rename(1to2) of a binary file
+#   Commit O: orig
+#   Commit A: orig-A
+#   Commit B: orig-B
+#   Expected: CONFLICT(rename/rename) message, three unstaged entries in the
+#             index, and contents of orig-[AB] at path orig-[AB]
+test_setup_rename_rename_1_to_2_binary () {
+	test_create_repo rename_rename_1_to_2_binary &&
+	(
+		cd rename_rename_1_to_2_binary &&
+
+		echo '* binary' >.gitattributes &&
+		git add .gitattributes &&
+
+		test_seq 1 10 >orig &&
+		git add orig &&
+		git commit -m orig &&
+
+		git branch A &&
+		git branch B &&
+
+		git checkout A &&
+		git mv orig orig-A &&
+		test_seq 1 11 >orig-A &&
+		git add orig-A &&
+		git commit -m orig-A &&
+
+		git checkout B &&
+		git mv orig orig-B &&
+		test_seq 0 10 >orig-B &&
+		git add orig-B &&
+		git commit -m orig-B
+
+	)
+}
+
+test_expect_success 'rename/rename(1to2) with a binary file' '
+	test_setup_rename_rename_1_to_2_binary &&
+	(
+		cd rename_rename_1_to_2_binary &&
+
+		git checkout A^0 &&
+
+		test_must_fail git merge -s recursive B^0 &&
+
+		# Make sure the index has the right number of entries
+		git ls-files -s >actual &&
+		test_line_count = 4 actual &&
+
+		git rev-parse A:orig-A B:orig-B >expect &&
+		git hash-object orig-A orig-B >actual &&
+		test_cmp expect actual
+	)
+'
+
 test_done