[7094] Fix empty save people groups (#7137)

* fix empty save people groups

* fix

lib/core/form/components/widgets/core/form-field.model.spec.ts

@@ -612,6 +612,31 @@ describe('FormFieldModel', () => {
         expect(form.values['dropdown_field'].name).toEqual('Option 1');
     });
 
+    it('should parse and resolve people null value as null', () => {
+        const field = new FormFieldModel(new FormModel(), {
+            type: FormFieldTypes.PEOPLE,
+            value: null
+        });
+
+        field.updateForm();
+
+        expect(field.value).toBe(null);
+    });
+
+    it('should parse and resolve people undefined value as null', () => {
+        const field = new FormFieldModel(new FormModel(), {
+            fieldType: 'HeaderFieldtype',
+            id: 'people_field',
+            name: 'people',
+            type: FormFieldTypes.PEOPLE,
+            value: undefined
+        });
+
+        field.updateForm();
+
+        expect(field.value).toBe(null);
+    });
+
     describe('variables', () => {
 
         let form: FormModel;
@@ -680,5 +705,6 @@ describe('FormFieldModel', () => {
 
             expect(field.value).toBe('default hello');
         });
+
     });
 });

lib/core/form/components/widgets/core/form-field.model.ts

@@ -268,7 +268,7 @@ export class FormFieldModel extends FormWidgetModel {
     }
 
     parseValue(json: any): any {
-        let value = json.hasOwnProperty('value') ? json.value : null;
+        let value = json.hasOwnProperty('value') && json.value !== undefined ? json.value : null;
 
         /*
          This is needed due to Activiti issue related to reading dropdown values as value string
@@ -408,10 +408,10 @@ export class FormFieldModel extends FormWidgetModel {
                 this.form.values[this.id] = (this.value !== null && this.value !== undefined) ? this.value : false;
                 break;
             case FormFieldTypes.PEOPLE:
-                this.form.values[this.id] = (this.value !== null && this.value !== undefined) ? this.value : [];
+                this.form.values[this.id] = this.value ? this.value : null;
                 break;
             case FormFieldTypes.FUNCTIONAL_GROUP:
-                this.form.values[this.id] = (this.value !== null && this.value !== undefined) ? this.value : [];
+                this.form.values[this.id] = this.value ? this.value : null;
                 break;
             default:
                 if (!FormFieldTypes.isReadOnlyType(this.type) && !this.isInvalidFieldType(this.type)) {