[Bug] NPE in KotlinDeprecatedPropertyCustomizer - resolvedSchema is null. Fixes #3121

Author: bnasslahsen

springdoc-openapi-starter-common/src/main/java/org/springdoc/core/customizers/KotlinDeprecatedPropertyCustomizer.kt

@@ -64,7 +64,7 @@ class KotlinDeprecatedPropertyCustomizer(
 			prop.hasAnnotation<Deprecated>()
 			if (deprecatedAnnotation != null) {
 				val fieldName = prop.name
-				if (resolvedSchema.`$ref` != null) {
+				if (resolvedSchema!=null && resolvedSchema.`$ref` != null) {
 					val schema =
 						context.getDefinedModels()[resolvedSchema.`$ref`.substring(
 							Components.COMPONENTS_SCHEMAS_REF.length

springdoc-openapi-tests/springdoc-openapi-kotlin-webmvc-tests/src/test/kotlin/test/org/springdoc/api/v31/app22/SpringDocApp22Test.kt

@@ -0,0 +1,58 @@
+/*
+ *
+ *  * Copyright 2019-2020 the original author or authors.
+ *  *
+ *  * Licensed under the Apache License, Version 2.0 (the "License");
+ *  * you may not use this file except in compliance with the License.
+ *  * You may obtain a copy of the License at
+ *  *
+ *  *      https://www.apache.org/licenses/LICENSE-2.0
+ *  *
+ *  * Unless required by applicable law or agreed to in writing, software
+ *  * distributed under the License is distributed on an "AS IS" BASIS,
+ *  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  * See the License for the specific language governing permissions and
+ *  * limitations under the License.
+ *
+ */
+
+package test.org.springdoc.api.v31.app22
+
+import com.fasterxml.jackson.annotation.JsonUnwrapped
+import io.swagger.v3.oas.annotations.Parameter
+import io.swagger.v3.oas.annotations.enums.Explode
+import io.swagger.v3.oas.annotations.media.ArraySchema
+import io.swagger.v3.oas.annotations.media.Schema
+import jakarta.validation.Valid
+import org.springdoc.core.annotations.ParameterObject
+import org.springframework.boot.autoconfigure.SpringBootApplication
+import org.springframework.http.ResponseEntity
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.RequestMapping
+import org.springframework.web.bind.annotation.RestController
+import test.org.springdoc.api.v31.AbstractKotlinSpringDocMVCTest
+
+class SpringDocApp22Test : AbstractKotlinSpringDocMVCTest() {
+	@SpringBootApplication
+	class DemoApplication
+}
+
+
+
+@RestController
+@RequestMapping("/test")
+@SpringBootApplication
+class DemoApp {
+	@GetMapping
+	fun getTestData(): Foo = Foo(bar = Bar(baz = "test"))
+}
+
+data class Foo(
+	@field:JsonUnwrapped
+	val bar: Bar,
+)
+
+data class Bar(
+	@Deprecated("This is deprecated")
+	val baz: String,
+)

springdoc-openapi-tests/springdoc-openapi-kotlin-webmvc-tests/src/test/resources/results/3.1.0/app22.json

@@ -0,0 +1,50 @@
+{
+  "openapi": "3.1.0",
+  "info": {
+    "title": "OpenAPI definition",
+    "version": "v0"
+  },
+  "servers": [
+    {
+      "url": "http://localhost",
+      "description": "Generated server url"
+    }
+  ],
+  "paths": {
+    "/test": {
+      "get": {
+        "tags": [
+          "demo-app"
+        ],
+        "operationId": "getTestData",
+        "responses": {
+          "200": {
+            "description": "OK",
+            "content": {
+              "*/*": {
+                "schema": {
+                  "$ref": "#/components/schemas/Foo"
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  },
+  "components": {
+    "schemas": {
+      "Foo": {
+        "type": "object",
+        "properties": {
+          "baz": {
+            "type": "string"
+          }
+        },
+        "required": [
+          "baz"
+        ]
+      }
+    }
+  }
+}