diff --git a/builtin/merge-recursive.c b/builtin/merge-recursive.c
index abfc060e28..03b5100cfa 100644
--- a/builtin/merge-recursive.c
+++ b/builtin/merge-recursive.c
@@ -3,7 +3,7 @@
 #include "advice.h"
 #include "gettext.h"
 #include "hash.h"
-#include "merge-recursive.h"
+#include "merge-ort-wrappers.h"
 #include "object-name.h"
 
 static const char builtin_merge_recursive_usage[] =
@@ -89,7 +89,7 @@ int cmd_merge_recursive(int argc,
 	if (o.verbosity >= 3)
 		printf(_("Merging %s with %s\n"), o.branch1, o.branch2);
 
-	failed = merge_recursive_generic(&o, &h1, &h2, bases_count, bases, &result);
+	failed = merge_ort_generic(&o, &h1, &h2, bases_count, bases, &result);
 
 	free(better1);
 	free(better2);
diff --git a/t/t6424-merge-unrelated-index-changes.sh b/t/t6424-merge-unrelated-index-changes.sh
index 7677c5f08d..084bfe7e6c 100755
--- a/t/t6424-merge-unrelated-index-changes.sh
+++ b/t/t6424-merge-unrelated-index-changes.sh
@@ -176,9 +176,11 @@ test_expect_success 'merge-recursive, when index==head but head!=HEAD' '
 	# Make index match B
 	git diff C B -- | git apply --cached &&
 	test_when_finished "git clean -fd" &&  # Do not leave untracked around
+	git write-tree >index-before &&
 	# Merge B & F, with B as "head"
 	git merge-recursive A -- B F > out &&
-	test_grep "Already up to date" out
+	git write-tree >index-after &&
+	test_cmp index-before index-after
 '
 
 test_expect_success 'recursive, when file has staged changes not matching HEAD nor what a merge would give' '
diff --git a/t/t6430-merge-recursive.sh b/t/t6430-merge-recursive.sh
index ca15e6dd6d..c539a68fd0 100755
--- a/t/t6430-merge-recursive.sh
+++ b/t/t6430-merge-recursive.sh
@@ -373,9 +373,9 @@ test_expect_success 'merge-recursive d/f conflict result' '
 
 	git ls-files -s >actual &&
 	(
-		echo "100644 $o0 1	a" &&
-		echo "100644 $o1 2	a" &&
 		echo "100644 $o4 0	a/c" &&
+		echo "100644 $o0 1	a~$c1" &&
+		echo "100644 $o1 2	a~$c1" &&
 		echo "100644 $o0 0	b" &&
 		echo "100644 $o0 0	c" &&
 		echo "100644 $o1 0	d/e"
@@ -397,9 +397,9 @@ test_expect_success 'merge-recursive d/f conflict result the other way' '
 
 	git ls-files -s >actual &&
 	(
-		echo "100644 $o0 1	a" &&
-		echo "100644 $o1 3	a" &&
 		echo "100644 $o4 0	a/c" &&
+		echo "100644 $o0 1	a~$c1" &&
+		echo "100644 $o1 3	a~$c1" &&
 		echo "100644 $o0 0	b" &&
 		echo "100644 $o0 0	c" &&
 		echo "100644 $o1 0	d/e"
@@ -424,9 +424,9 @@ 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 3	d" &&
 		echo "100644 $o0 1	d/e" &&
-		echo "100644 $o1 2	d/e"
+		echo "100644 $o1 2	d/e" &&
+		echo "100644 $o6 3	d~$c6"
 	) >expected &&
 	test_cmp expected actual
 
@@ -448,9 +448,9 @@ 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 $o0 1	d/e" &&
-		echo "100644 $o1 3	d/e"
+		echo "100644 $o1 3	d/e" &&
+		echo "100644 $o6 2	d~$c6"
 	) >expected &&
 	test_cmp expected actual
 
@@ -696,33 +696,6 @@ test_expect_success 'merging with triple rename across D/F conflict' '
 	git merge other
 '
 
-test_expect_success 'merge-recursive remembers the names of all base trees' '
-	git reset --hard HEAD &&
-
-	# make the index match $c1 so that merge-recursive below does not
-	# fail early
-	git diff --binary HEAD $c1 -- | git apply --cached &&
-
-	# more trees than static slots used by oid_to_hex()
-	for commit in $c0 $c2 $c4 $c5 $c6 $c7
-	do
-		git rev-parse "$commit^{tree}" || return 1
-	done >trees &&
-
-	# ignore the return code; it only fails because the input is weird...
-	test_must_fail git -c merge.verbosity=5 merge-recursive $(cat trees) -- $c1 $c3 >out &&
-
-	# ...but make sure it fails in the expected way
-	test_grep CONFLICT.*rename/rename out &&
-
-	# merge-recursive prints in reverse order, but we do not care
-	sort <trees >expect &&
-	sed -n "s/^virtual //p" out | sort >actual &&
-	test_cmp expect actual &&
-
-	git clean -fd
-'
-
 test_expect_success 'merge-recursive internal merge resolves to the sameness' '
 	git reset --hard HEAD &&
 
diff --git a/t/t6434-merge-recursive-rename-options.sh b/t/t6434-merge-recursive-rename-options.sh
index 6e913c30a1..5a6f74839c 100755
--- a/t/t6434-merge-recursive-rename-options.sh
+++ b/t/t6434-merge-recursive-rename-options.sh
@@ -34,7 +34,9 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 get_expected_stages () {
 	git checkout rename -- $1-new &&
 	git ls-files --stage $1-new >expected-stages-undetected-$1 &&
-	sed "s/ 0	/ 2	/" <expected-stages-undetected-$1 \
+	git ls-tree HEAD^ $1-old >tmp &&
+	git ls-tree HEAD  $1-new >>tmp &&
+	cat tmp | awk '{print $1 " " $3 " " NR "\t" '$1'"-new"}' \
 		>expected-stages-detected-$1 &&
 	git read-tree -u --reset HEAD
 }
@@ -51,11 +53,11 @@ rename_undetected () {
 
 check_common () {
 	git ls-files --stage >stages-actual &&
-	test_line_count = 4 stages-actual
+	test_line_count = $1 stages-actual
 }
 
 check_threshold_0 () {
-	check_common &&
+	check_common 8 &&
 	rename_detected 0 &&
 	rename_detected 1 &&
 	rename_detected 2 &&
@@ -63,7 +65,7 @@ check_threshold_0 () {
 }
 
 check_threshold_1 () {
-	check_common &&
+	check_common 7 &&
 	rename_undetected 0 &&
 	rename_detected 1 &&
 	rename_detected 2 &&
@@ -71,7 +73,7 @@ check_threshold_1 () {
 }
 
 check_threshold_2 () {
-	check_common &&
+	check_common 6 &&
 	rename_undetected 0 &&
 	rename_undetected 1 &&
 	rename_detected 2 &&
@@ -79,7 +81,7 @@ check_threshold_2 () {
 }
 
 check_exact_renames () {
-	check_common &&
+	check_common 5 &&
 	rename_undetected 0 &&
 	rename_undetected 1 &&
 	rename_undetected 2 &&
@@ -87,7 +89,7 @@ check_exact_renames () {
 }
 
 check_no_renames () {
-	check_common &&
+	check_common 4 &&
 	rename_undetected 0 &&
 	rename_undetected 1 &&
 	rename_undetected 2 &&