Step to reproduces

bin/configs/kotlin-allOff-discriminator.yaml

@@ -0,0 +1,9 @@
+generatorName: kotlin
+outputDir: samples/client/petstore/kotlin-allOff-discriminator
+inputSpec: modules/openapi-generator/src/test/resources/3_0/issue_10792.yaml
+templateDir: modules/openapi-generator/src/main/resources/kotlin-client
+additionalProperties:
+  artifactId: kotlin-allOff-discriminator
+  serializableModel: "false"
+  dateLibrary: java8
+  enumUnknownDefaultCase: true

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

@@ -272,4 +272,33 @@ public void testEnumPropertyWithDefaultValue() {
         Assert.assertEquals(cp1.getEnumName(), "PropertyName");
         Assert.assertEquals(cp1.getDefaultValue(), "PropertyName.vALUE");
     }
+
+    @Test(description = "Issue #10792")
+    public void handleInheritanceWithObjectTypeShouldNotBeAMap() {
+        Schema parent = new ObjectSchema()
+            .addProperties("a", new StringSchema())
+            .addProperties("b", new StringSchema())
+            .addRequiredItem("a")
+            .name("Parent");
+        Schema child = new ComposedSchema()
+            .addAllOfItem(new Schema().$ref("Parent"))
+            .addAllOfItem(new ObjectSchema()
+                .addProperties("c", new StringSchema())
+                .addProperties("d", new StringSchema())
+                .addRequiredItem("c"))
+            .name("Child")
+            .type("object"); // Without the object type it is not wrongly recognized as map
+
+        OpenAPI openAPI = TestUtils.createOpenAPI();
+        openAPI.getComponents().addSchemas(parent.getName(), parent);
+        openAPI.getComponents().addSchemas(child.getName(), child);
+
+        final DefaultCodegen codegen = new P_AbstractKotlinCodegen();
+        codegen.setOpenAPI(openAPI);
+
+        final CodegenModel pm = codegen
+            .fromModel("Child", child);
+
+        Assert.assertFalse(pm.isMap);
+    }
 }

modules/openapi-generator/src/test/resources/3_0/issue_10792.yaml

@@ -0,0 +1,57 @@
+openapi: 3.0.1
+info:
+  title: Example
+  description: An example
+  version: '0.1'
+  contact:
+    email: contact@example.org
+    url: 'https://example.org'
+servers:
+  - url: http://example.org
+tags:
+  - name: bird
+paths:
+  '/v1/bird/{id}':
+    get:
+      tags:
+        - bird
+      responses:
+        '200':
+          description: OK
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/bird'
+      operationId: get-bird
+    parameters:
+      - schema:
+          type: string
+          format: uuid
+        name: id
+        in: path
+        required: true
+components:
+  schemas:
+    animal:
+      title: An animal
+      type: object
+      properties:
+        id:
+          type: string
+          format: uuid
+      required:
+        - id
+      discriminator:
+        propertyName: type
+        mapping:
+          BIRD: '#/components/schemas/bird'
+    bird:
+      title: A bird
+      type: object
+      allOf:
+        - $ref: '#/components/schemas/animal'
+        - properties:
+            featherType:
+              type: string
+          required:
+            - featherType

samples/client/petstore/kotlin-allOff-discriminator/.openapi-generator-ignore

@@ -0,0 +1,23 @@
+# OpenAPI Generator Ignore
+# Generated by openapi-generator https://github.com/openapitools/openapi-generator
+
+# Use this file to prevent files from being overwritten by the generator.
+# The patterns follow closely to .gitignore or .dockerignore.
+
+# As an example, the C# client generator defines ApiClient.cs.
+# You can make changes and tell OpenAPI Generator to ignore just this file by uncommenting the following line:
+#ApiClient.cs
+
+# You can match any string of characters against a directory, file or extension with a single asterisk (*):
+#foo/*/qux
+# The above matches foo/bar/qux and foo/baz/qux, but not foo/bar/baz/qux
+
+# You can recursively match patterns against a directory, file or extension with a double asterisk (**):
+#foo/**/qux
+# This matches foo/bar/qux, foo/baz/qux, and foo/bar/baz/qux
+
+# You can also negate patterns with an exclamation (!).
+# For example, you can ignore all files in a docs folder with the file extension .md:
+#docs/*.md
+# Then explicitly reverse the ignore rule for a single file:
+#!docs/README.md

samples/client/petstore/kotlin-allOff-discriminator/.openapi-generator/FILES

@@ -0,0 +1,33 @@
+README.md
+build.gradle
+docs/Animal.md
+docs/Bird.md
+docs/BirdAllOf.md
+docs/BirdApi.md
+gradle/wrapper/gradle-wrapper.jar
+gradle/wrapper/gradle-wrapper.properties
+gradlew
+gradlew.bat
+settings.gradle
+src/main/kotlin/org/openapitools/client/apis/BirdApi.kt
+src/main/kotlin/org/openapitools/client/infrastructure/ApiAbstractions.kt
+src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt
+src/main/kotlin/org/openapitools/client/infrastructure/ApiResponse.kt
+src/main/kotlin/org/openapitools/client/infrastructure/BigDecimalAdapter.kt
+src/main/kotlin/org/openapitools/client/infrastructure/BigIntegerAdapter.kt
+src/main/kotlin/org/openapitools/client/infrastructure/ByteArrayAdapter.kt
+src/main/kotlin/org/openapitools/client/infrastructure/Errors.kt
+src/main/kotlin/org/openapitools/client/infrastructure/LocalDateAdapter.kt
+src/main/kotlin/org/openapitools/client/infrastructure/LocalDateTimeAdapter.kt
+src/main/kotlin/org/openapitools/client/infrastructure/OffsetDateTimeAdapter.kt
+src/main/kotlin/org/openapitools/client/infrastructure/PartConfig.kt
+src/main/kotlin/org/openapitools/client/infrastructure/RequestConfig.kt
+src/main/kotlin/org/openapitools/client/infrastructure/RequestMethod.kt
+src/main/kotlin/org/openapitools/client/infrastructure/ResponseExtensions.kt
+src/main/kotlin/org/openapitools/client/infrastructure/Serializer.kt
+src/main/kotlin/org/openapitools/client/infrastructure/SerializerHelper.kt
+src/main/kotlin/org/openapitools/client/infrastructure/URIAdapter.kt
+src/main/kotlin/org/openapitools/client/infrastructure/UUIDAdapter.kt
+src/main/kotlin/org/openapitools/client/models/Animal.kt
+src/main/kotlin/org/openapitools/client/models/Bird.kt
+src/main/kotlin/org/openapitools/client/models/BirdAllOf.kt

samples/client/petstore/kotlin-allOff-discriminator/.openapi-generator/VERSION

@@ -0,0 +1 @@
+6.0.1-SNAPSHOT

samples/client/petstore/kotlin-allOff-discriminator/README.md

@@ -0,0 +1,52 @@
+# org.openapitools.client - Kotlin client library for Example
+
+## Requires
+
+* Kotlin 1.4.30
+* Gradle 6.8.3
+
+## Build
+
+First, create the gradle wrapper script:
+
+```
+gradle wrapper
+```
+
+Then, run:
+
+```
+./gradlew check assemble
+```
+
+This runs all tests and packages the library.
+
+## Features/Implementation Notes
+
+* Supports JSON inputs/outputs, File inputs, and Form inputs.
+* Supports collection formats for query parameters: csv, tsv, ssv, pipes.
+* Some Kotlin and Java types are fully qualified to avoid conflicts with types defined in OpenAPI definitions.
+* Implementation of ApiClient is intended to reduce method counts, specifically to benefit Android targets.
+
+<a name="documentation-for-api-endpoints"></a>
+## Documentation for API Endpoints
+
+All URIs are relative to *http://example.org*
+
+Class | Method | HTTP request | Description
+------------ | ------------- | ------------- | -------------
+*BirdApi* | [**getBird**](docs/BirdApi.md#getbird) | **GET** /v1/bird/{id} | 
+
+
+<a name="documentation-for-models"></a>
+## Documentation for Models
+
+ - [org.openapitools.client.models.Animal](docs/Animal.md)
+ - [org.openapitools.client.models.Bird](docs/Bird.md)
+ - [org.openapitools.client.models.BirdAllOf](docs/BirdAllOf.md)
+
+
+<a name="documentation-for-authorization"></a>
+## Documentation for Authorization
+
+All endpoints do not require authorization.

samples/client/petstore/kotlin-allOff-discriminator/build.gradle

@@ -0,0 +1,37 @@
+group 'org.openapitools'
+version '1.0.0'
+
+wrapper {
+    gradleVersion = '6.8.3'
+    distributionUrl = "https://services.gradle.org/distributions/gradle-$gradleVersion-all.zip"
+}
+
+buildscript {
+    ext.kotlin_version = '1.5.10'
+
+    repositories {
+        maven { url "https://repo1.maven.org/maven2" }
+    }
+    dependencies {
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+    }
+}
+
+apply plugin: 'kotlin'
+
+repositories {
+    maven { url "https://repo1.maven.org/maven2" }
+}
+
+test {
+    useJUnitPlatform()
+}
+
+dependencies {
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
+    implementation "org.jetbrains.kotlin:kotlin-reflect:$kotlin_version"
+    implementation "com.squareup.moshi:moshi-kotlin:1.12.0"
+    implementation "com.squareup.moshi:moshi-adapters:1.12.0"
+    implementation "com.squareup.okhttp3:okhttp:4.9.1"
+    testImplementation "io.kotlintest:kotlintest-runner-junit5:3.4.2"
+}

samples/client/petstore/kotlin-allOff-discriminator/docs/Animal.md

@@ -0,0 +1,10 @@
+
+# Animal
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**id** | [**java.util.UUID**](java.util.UUID.md) |  | 
+
+
+

samples/client/petstore/kotlin-allOff-discriminator/docs/Bird.md

@@ -0,0 +1,10 @@
+
+# Bird
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**featherType** | **kotlin.String** |  | 
+
+
+

samples/client/petstore/kotlin-allOff-discriminator/docs/BirdAllOf.md

@@ -0,0 +1,10 @@
+
+# BirdAllOf
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**featherType** | **kotlin.String** |  | 
+
+
+

samples/client/petstore/kotlin-allOff-discriminator/docs/BirdApi.md

@@ -0,0 +1,54 @@
+# BirdApi
+
+All URIs are relative to *http://example.org*
+
+Method | HTTP request | Description
+------------- | ------------- | -------------
+[**getBird**](BirdApi.md#getBird) | **GET** /v1/bird/{id} | 
+
+
+<a name="getBird"></a>
+# **getBird**
+> Bird getBird(id)
+
+
+
+### Example
+```kotlin
+// Import classes:
+//import org.openapitools.client.infrastructure.*
+//import org.openapitools.client.models.*
+
+val apiInstance = BirdApi()
+val id : java.util.UUID = 38400000-8cf0-11bd-b23e-10b96e4ef00d // java.util.UUID | 
+try {
+    val result : Bird = apiInstance.getBird(id)
+    println(result)
+} catch (e: ClientException) {
+    println("4xx response calling BirdApi#getBird")
+    e.printStackTrace()
+} catch (e: ServerException) {
+    println("5xx response calling BirdApi#getBird")
+    e.printStackTrace()
+}
+```
+
+### Parameters
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **id** | **java.util.UUID**|  |
+
+### Return type
+
+[**Bird**](Bird.md)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: Not defined
+ - **Accept**: application/json
+

samples/client/petstore/kotlin-allOff-discriminator/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.8.3-all.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists