diff --git a/merge-ort.c b/merge-ort.c
index d49cfa8b03..f8f7d06d48 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -512,6 +512,77 @@ static char *unique_path(struct strmap *existing_paths,
 
 /*** Function Grouping: functions related to collect_merge_info() ***/
 
+static int traverse_trees_wrapper_callback(int n,
+					   unsigned long mask,
+					   unsigned long dirmask,
+					   struct name_entry *names,
+					   struct traverse_info *info)
+{
+	struct merge_options *opt = info->data;
+	struct rename_info *renames = &opt->priv->renames;
+
+	assert(n==3);
+
+	if (!renames->callback_data_traverse_path)
+		renames->callback_data_traverse_path = xstrdup(info->traverse_path);
+
+	ALLOC_GROW(renames->callback_data, renames->callback_data_nr + 1,
+		   renames->callback_data_alloc);
+	renames->callback_data[renames->callback_data_nr].mask = mask;
+	renames->callback_data[renames->callback_data_nr].dirmask = dirmask;
+	COPY_ARRAY(renames->callback_data[renames->callback_data_nr].names,
+		   names, 3);
+	renames->callback_data_nr++;
+
+	return mask;
+}
+
+/*
+ * Much like traverse_trees(), BUT:
+ *   - read all the tree entries FIRST, saving them
+ *   - note that the above step provides an opportunity to compute necessary
+ *     additional details before the "real" traversal
+ *   - loop through the saved entries and call the original callback on them
+ */
+MAYBE_UNUSED
+static int traverse_trees_wrapper(struct index_state *istate,
+				  int n,
+				  struct tree_desc *t,
+				  struct traverse_info *info)
+{
+	int ret, i, old_offset;
+	traverse_callback_t old_fn;
+	char *old_callback_data_traverse_path;
+	struct merge_options *opt = info->data;
+	struct rename_info *renames = &opt->priv->renames;
+
+	old_callback_data_traverse_path = renames->callback_data_traverse_path;
+	old_fn = info->fn;
+	old_offset = renames->callback_data_nr;
+
+	renames->callback_data_traverse_path = NULL;
+	info->fn = traverse_trees_wrapper_callback;
+	ret = traverse_trees(istate, n, t, info);
+	if (ret < 0)
+		return ret;
+
+	info->traverse_path = renames->callback_data_traverse_path;
+	info->fn = old_fn;
+	for (i = old_offset; i < renames->callback_data_nr; ++i) {
+		info->fn(n,
+			 renames->callback_data[i].mask,
+			 renames->callback_data[i].dirmask,
+			 renames->callback_data[i].names,
+			 info);
+	}
+
+	renames->callback_data_nr = old_offset;
+	free(renames->callback_data_traverse_path);
+	renames->callback_data_traverse_path = old_callback_data_traverse_path;
+	info->traverse_path = NULL;
+	return 0;
+}
+
 static void setup_path_info(struct merge_options *opt,
 			    struct string_list_item *result,
 			    const char *current_dir_name,