From d13b8231c52f8015ee040254779331953bf0c391 Mon Sep 17 00:00:00 2001
From: Bastien Jansen <bastien.jansen@gmx.com>
Date: Wed, 21 Feb 2024 08:22:46 +0100
Subject: [PATCH] Fix `ClassCastException` in `OpenAPINormalizer` on composed
 schemas in 3.1 (#17912)

---
 .../codegen/OpenAPINormalizer.java            | 26 +++++++-------
 .../codegen/OpenAPINormalizerTest.java        | 10 +++++-
 .../test/resources/3_1/composed-schema.yaml   | 36 +++++++++++++++++++
 3 files changed, 57 insertions(+), 15 deletions(-)
 create mode 100644 modules/openapi-generator/src/test/resources/3_1/composed-schema.yaml

diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/OpenAPINormalizer.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/OpenAPINormalizer.java
index ffc5235ea102..2eed307c7beb 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/OpenAPINormalizer.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/OpenAPINormalizer.java
@@ -458,33 +458,31 @@ public Schema normalizeSchema(Schema schema, Set<Schema> visitedSchemas) {
         } else if (ModelUtils.isAllOf(schema)) { // allOf
             return normalizeAllOf(schema, visitedSchemas);
         } else if (ModelUtils.isComposedSchema(schema)) { // composed schema
-            ComposedSchema cs = (ComposedSchema) schema;
-
-            if (ModelUtils.isComplexComposedSchema(cs)) {
-                cs = (ComposedSchema) normalizeComplexComposedSchema(cs, visitedSchemas);
+            if (ModelUtils.isComplexComposedSchema(schema)) {
+                schema = normalizeComplexComposedSchema(schema, visitedSchemas);
             }
 
-            if (cs.getAllOf() != null && !cs.getAllOf().isEmpty()) {
-                return normalizeAllOf(cs, visitedSchemas);
+            if (schema.getAllOf() != null && !schema.getAllOf().isEmpty()) {
+                return normalizeAllOf(schema, visitedSchemas);
             }
 
-            if (cs.getOneOf() != null && !cs.getOneOf().isEmpty()) {
-                return normalizeOneOf(cs, visitedSchemas);
+            if (schema.getOneOf() != null && !schema.getOneOf().isEmpty()) {
+                return normalizeOneOf(schema, visitedSchemas);
             }
 
-            if (cs.getAnyOf() != null && !cs.getAnyOf().isEmpty()) {
-                return normalizeAnyOf(cs, visitedSchemas);
+            if (schema.getAnyOf() != null && !schema.getAnyOf().isEmpty()) {
+                return normalizeAnyOf(schema, visitedSchemas);
             }
 
-            if (cs.getProperties() != null && !cs.getProperties().isEmpty()) {
-                normalizeProperties(cs.getProperties(), visitedSchemas);
+            if (schema.getProperties() != null && !schema.getProperties().isEmpty()) {
+                normalizeProperties(schema.getProperties(), visitedSchemas);
             }
 
-            if (cs.getAdditionalProperties() != null) {
+            if (schema.getAdditionalProperties() != null) {
                 // normalizeAdditionalProperties(m);
             }
 
-            return cs;
+            return schema;
         } else if (schema.getProperties() != null && !schema.getProperties().isEmpty()) {
             normalizeProperties(schema.getProperties(), visitedSchemas);
         } else if (schema instanceof BooleanSchema) {
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/OpenAPINormalizerTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/OpenAPINormalizerTest.java
index 2694910817a8..05253ca2f194 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/OpenAPINormalizerTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/OpenAPINormalizerTest.java
@@ -467,4 +467,12 @@ public void testFilter() {
         assertEquals(openAPI.getPaths().get("/person/display/{personId}").getDelete().getExtensions().get("x-internal"), false);
         assertEquals(openAPI.getPaths().get("/person/display/{personId}").getPut().getExtensions().get("x-internal"), true);
     }
-}
\ No newline at end of file
+
+    @Test
+    public void testComposedSchemaDoesNotThrow() {
+        OpenAPI openAPI = TestUtils.parseSpec("src/test/resources/3_1/composed-schema.yaml");
+
+        OpenAPINormalizer openAPINormalizer = new OpenAPINormalizer(openAPI, Collections.emptyMap());
+        openAPINormalizer.normalize();
+    }
+}
diff --git a/modules/openapi-generator/src/test/resources/3_1/composed-schema.yaml b/modules/openapi-generator/src/test/resources/3_1/composed-schema.yaml
new file mode 100644
index 000000000000..5b89638e1e37
--- /dev/null
+++ b/modules/openapi-generator/src/test/resources/3_1/composed-schema.yaml
@@ -0,0 +1,36 @@
+openapi: 3.1.0
+info:
+  version: 1.0.0
+  title: Example
+  license:
+    name: MIT
+servers:
+  - url: http://api.example.xyz/v1
+paths:
+  /payment:
+    post:
+      operationId: payment
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/Payment"
+
+components:
+  schemas:
+    Payment:
+      type: object
+      properties:
+        label:
+          type: string
+        otherLabel:
+          type: string
+        amount:
+          type: number
+      oneOf:
+        - required:
+            - label
+            - amount
+        - required:
+            - otherLabel
+            - amount