fix d2oracle

d2oracle/edit.go

@@ -2066,7 +2066,13 @@ func hasSpace(tag string) bool {
 }
 
 func getMostNestedRefs(obj *d2graph.Object) []d2graph.Reference {
-	most := obj.References[0]
+	var most d2graph.Reference
+	for _, ref := range obj.References {
+		if len(ref.MapKey.Edges) == 0 {
+			most = ref
+			break
+		}
+	}
 	for _, ref := range obj.References {
 		if len(ref.MapKey.Edges) != 0 {
 			continue

d2oracle/edit_test.go

@@ -2001,6 +2001,32 @@ c: {
 				assert.JSON(t, len(g.Objects), 3)
 			},
 		},
+		{
+			name: "underscore-connection",
+
+			text: `a: {
+  b
+
+  _.c.d -> b
+}
+
+c: {
+  d
+}
+`,
+			key:    `a.b`,
+			newKey: `c.b`,
+
+			exp: `a: {
+  _.c.d -> _.c.b
+}
+
+c: {
+  d
+  b
+}
+`,
+		},
 		{
 			name: "flat_middle_container",