Descriptions of a composite component's fields appear duplicated in t…

…he Translation tab fix #8238 (#8239)

src/jsonobject.ts

@@ -1160,9 +1160,17 @@ export class JsonMetadata {
     return metaClass.getAllProperties();
   }
   public getPropertiesByObj(obj: any): Array<JsonObjectProperty> {
-    if (!obj || !obj.getType) return [];
-    const props = this.getProperties(obj.getType());
+    const type = !!obj && !!obj.getType ? obj.getType() : undefined;
+    if (!type) return [];
+    const props = this.getProperties(type);
     const dynamicProps = this.getDynamicPropertiesByObj(obj);
+    for(let i = dynamicProps.length -1; i >= 0; i --) {
+      if(this.findProperty(type, dynamicProps[i].name)) {
+        dynamicProps.splice(i, 1);
+      }
+    }
+    if(dynamicProps.length === 0) return props;
+
     return [].concat(props).concat(dynamicProps);
   }
   public addDynamicPropertiesIntoObj(dest: any, src: any, props: Array<JsonObjectProperty>): void {

tests/question_customtests.ts

@@ -3237,3 +3237,36 @@ QUnit.test("Single: use incorrect json", function (assert) {
   ComponentCollection.Instance.clear();
   ConsoleWarnings.error = prev;
 });
+QUnit.test("single component: inheritBaseProps - do not duplicate description property", function (assert) {
+  ComponentCollection.Instance.add({
+    name: "customdropdown",
+    inheritBaseProps: ["description"],
+    questionJSON: {
+      type: "dropdown",
+      description: {
+        en: "Custom Question",
+        de: "Aangepaste vraag"
+      },
+      choices: [1, 2, 3]
+    },
+  });
+
+  const survey = new SurveyModel({
+    elements: [
+      { type: "customdropdown", name: "q1" }
+    ]
+  });
+  const q1 = <QuestionCustomModel>survey.getQuestionByName("q1");
+  assert.equal(q1.description, "Custom Question", "Get description from internal description");
+  survey.locale = "de";
+  assert.equal(q1.description, "Aangepaste vraag", "Get description from internal description for 'de'");
+  const props = Serializer.getPropertiesByObj(q1);
+  let descriptionCounter = 0;
+  props.forEach(prop => {
+    if(prop.name === "description") {
+      descriptionCounter ++;
+    }
+  });
+  assert.equal(descriptionCounter, 1, "We have one description property");
+  ComponentCollection.Instance.clear();
+});