Fix building of allOf

Author: jpfinne

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

@@ -1690,7 +1690,7 @@ private Schema findProperty(Schema schema, String propertyName, boolean toDelete
             Schema property = properties.get(propertyName);
             if (property != null) {
                 if (toDelete) {
-                    if (schema.getProperties().remove(propertyName) != null) {
+                    if (schema.getProperties().remove(propertyName) != null && schema.getProperties().isEmpty()) {
                         schema.setProperties(null);
                     }
                 }
@@ -1752,10 +1752,11 @@ protected void ensureInheritanceForDiscriminatorMappings(Schema parent, Schema c
             child.setAllOf(allOf);
             Schema refToParent = new Schema<>().$ref(reference);
             allOf.add(refToParent);
-            if (child.getProperties() != null) {
+            Map<String, Schema> childProperties = child.getProperties();
+            if (childProperties != null) {
                 // move the properties inside the new allOf.
-                Schema childProperties = new Schema<>().properties(child.getProperties());
-                allOf.add(childProperties);
+                Schema newChildProperties = new Schema<>().properties(childProperties);
+                allOf.add(newChildProperties);
                 child.setProperties(null);
                 child.setType(null);
             }

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

@@ -16,9 +16,6 @@
 
 package org.openapitools.codegen;
 
-import com.fasterxml.jackson.core.JsonProcessingException;
-import com.fasterxml.jackson.databind.ObjectMapper;
-import io.swagger.util.Yaml;
 import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.oas.models.Operation;
 import io.swagger.v3.oas.models.PathItem;
@@ -29,7 +26,6 @@
 import org.openapitools.codegen.utils.ModelUtils;
 import org.testng.annotations.Test;
 
-import java.lang.reflect.Array;
 import java.math.BigDecimal;
 import java.util.*;
 
@@ -1529,7 +1525,11 @@ public void issue_14769() {
         Map<String, String> mapping = vehicle.getDiscriminator().getMapping();
         assertEquals(mapping, Map.of("car", "#/components/schemas/Car", "plane", "#/components/schemas/Plane" ));
         Schema car = openAPI.getComponents().getSchemas().get("Car");
-        assertFalse(car.getProperties().containsKey("type"));
+        assertNull(car.getProperties());
+        assertEquals(car.getAllOf().size(), 2);
+        assertEquals(((Schema)car.getAllOf().get(0)).get$ref(), "#/components/schemas/Vehicle");
+        assertEquals(((Schema)car.getAllOf().get(1)).getProperties().size(), 1);
+        assertEquals(((Schema)car.getAllOf().get(1)).getProperties().keySet(), Set.of("has_4_wheel_drive"));
     }
 
     @Test