From 66cff2b05a39360788b86b1132a26b75f7314979 Mon Sep 17 00:00:00 2001
From: William Cheng <wing328hk@gmail.com>
Date: Mon, 10 Dec 2018 22:46:41 +0800
Subject: [PATCH] fix alias to free form object & map (#1638)

---
 .../org/openapitools/codegen/utils/ModelUtils.java     | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java
index 8ac76f74734..518a1c44892 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java
@@ -768,21 +768,23 @@ public class ModelUtils {
             } else if (ref.getEnum() != null && !ref.getEnum().isEmpty()) {
                 // top-level enum class
                 return schema;
-            } else if (isFreeFormObject(ref)) {
-                return schema;
             } else if (isArraySchema(ref)) {
                 return unaliasSchema(allSchemas, allSchemas.get(ModelUtils.getSimpleRef(schema.get$ref())));
             } else if (isComposedSchema(ref)) {
                 return schema;
             } else if (isMapSchema(ref)) {
-                if (ref.getProperties() != null && !ref.getProperties().isEmpty()) // has properties
+                if (ref.getProperties() != null && !ref.getProperties().isEmpty()) // has at least one property
                     return schema; // treat it as model
                 else {
                     // treat it as a typical map
                     return unaliasSchema(allSchemas, allSchemas.get(ModelUtils.getSimpleRef(schema.get$ref())));
                 }
             } else if (isObjectSchema(ref)) { // model
-                return schema;
+                if (ref.getProperties() != null && !ref.getProperties().isEmpty()) { // has at least one property
+                    return schema;
+                } else { // free form object (type: object)
+                    return unaliasSchema(allSchemas, allSchemas.get(ModelUtils.getSimpleRef(schema.get$ref())));
+                }
             } else {
                 return unaliasSchema(allSchemas, allSchemas.get(ModelUtils.getSimpleRef(schema.get$ref())));
             }