Auto fix invalid schemas in inline resolver

modules/openapi-generator/src/main/java/org/openapitools/codegen/InlineModelResolver.java

@@ -353,18 +353,22 @@ private void gatherInlineModels(Schema schema, String modelPrefix) {
                     }
                 }
             }
-        } else if (schema.getProperties() != null) {
-            // If non-object type is specified but also properties
-            LOGGER.error("Illegal schema found with non-object type combined with properties," +
-                    " no properties should be defined:\n " + schema.toString());
-            return;
-        } else if (schema.getAdditionalProperties() != null) {
-            // If non-object type is specified but also additionalProperties
-            LOGGER.error("Illegal schema found with non-object type combined with" +
-                    " additionalProperties, no additionalProperties should be defined:\n " +
-                    schema.toString());
-            return;
+        } else {
+            if (schema.getProperties() != null) {
+                // If non-object type is specified but also properties
+                LOGGER.warn("Illegal schema found with non-object type ({}) combined with properties. Properties automatically removed.", schema.getType());
+                schema.setProperties(null);
+                return;
+            }
+
+            if (schema.getAdditionalProperties() != null) {
+                // If non-object type is specified but also additionalProperties
+                LOGGER.error("Illegal schema found with non-object type ({}) combined with additionalProperties. AdditionalProperties automatically removed.", schema.getType());
+                schema.setAdditionalProperties(null);
+                return;
+            }
         }
+
         // Check array items
         if (ModelUtils.isArraySchema(schema)) {
             Schema items = ModelUtils.getSchemaItems(schema);

modules/openapi-generator/src/test/java/org/openapitools/codegen/InlineModelResolverTest.java

@@ -1205,4 +1205,13 @@ public void doNotWrapSingleAllOfRefs() {
         assertNotNull(allOfRefWithDescriptionAndReadonly.getAllOf());
         assertEquals(numberRangeRef, ((Schema) allOfRefWithDescriptionAndReadonly.getAllOf().get(0)).get$ref());
     }
+
+    @Test
+    public void testNonNullTypeWithProperties() {
+        OpenAPI openAPI = TestUtils.parseSpec("src/test/resources/3_0/issue_21680_array_with_properties.yaml");
+        new InlineModelResolver().flatten(openAPI);
+        Schema<?> schema = (Schema<?>) openAPI.getComponents().getSchemas().get("errors");
+        assertNotNull(schema);
+        assertNull(schema.getProperties());
+    }
 }

modules/openapi-generator/src/test/java/org/openapitools/codegen/java/spring/SpringCodegenTest.java

@@ -2272,8 +2272,12 @@ public void testResponseWithArray_issue12524() throws Exception {
             additionalProperties.put(RETURN_SUCCESS_CODE, "true");
             Map<String, File> files = generateFromContract("src/test/resources/bugs/issue_12524.json", SPRING_BOOT, additionalProperties);
 
-            JavaFileAssert.assertThat(files.get("API01ListOfStuff.java"))
-                    .hasImports("com.fasterxml.jackson.annotation.JsonTypeName");
+            // class extending array is no longer generated as it's automatically fixed by inline resolver
+            // by removing the properties for array type
+            //JavaFileAssert.assertThat(files.get("API01ListOfStuff.java"))
+            //        .hasImports("com.fasterxml.jackson.annotation.JsonTypeName");
+            File notExisting = files.get("API01ListOfStuff.java");
+            assertThat(notExisting).isNull();
         } finally {
             GlobalSettings.reset();
         }

modules/openapi-generator/src/test/resources/3_0/issue_21680_array_with_properties.yaml

@@ -0,0 +1,48 @@
+---
+# Corresponds to bug report 21680: https://github.com/openapitools/openapi-generator/issues/21680
+openapi: 3.0.1
+info:
+  title: API that has problem with OpenAPI Generator
+  version: 1.0.0
+paths:
+  "/forbiddenaccesscsrf":
+    get:
+      summary: Forbidden access CSRF
+      operationId: forbiddenAccessCsrfGet
+      responses:
+        '403':
+          description: Expected response
+          content:
+            application/json:
+              schema:
+                "$ref": "#/components/schemas/errors"
+components:
+  schemas:
+    error:
+      required:
+      - code
+      - horodatage
+      - message
+      type: object
+      properties:
+        code:
+          type: string
+          description: Short error description
+        message:
+          type: string
+          description: Complete human readable description
+        error_uri:
+          type: string
+          description: Detailed error description URI
+          format: uri
+        horodatage:
+          type: string
+          description: Date time of occurence
+          format: date-time
+    errors:
+      type: array
+      properties:
+        empty:
+          type: boolean
+      items:
+        "$ref": "#/components/schemas/error"