Fix ReferenceInput throws an error when referencing the same resource as Edit and the reference is undefined

packages/ra-core/src/dataProvider/useGetManyAggregate.ts

@@ -120,7 +120,7 @@ export const useGetManyAggregate = <RecordType extends RaRecord = any>(
             placeholderData,
             onSuccess: data => {
                 // optimistically populate the getOne cache
-                data.forEach(record => {
+                (data ?? []).forEach(record => {
                     queryClient.setQueryData(
                         [resource, 'getOne', { id: String(record.id), meta }],
                         oldRecord => oldRecord ?? record

packages/ra-ui-materialui/src/input/ReferenceInput.spec.tsx

@@ -16,6 +16,7 @@ import {
     Basic,
     WithSelectInput,
     dataProviderWithAuthors,
+    SelfReference,
 } from './ReferenceInput.stories';
 
 describe('<ReferenceInput />', () => {
@@ -217,4 +218,18 @@ describe('<ReferenceInput />', () => {
             })
         );
     });
+
+    it('should not throw an error on save when it is a self reference and the reference is undefined', async () => {
+        jest.spyOn(console, 'log').mockImplementationOnce(() => {});
+        jest.spyOn(console, 'error').mockImplementationOnce(() => {});
+        render(<SelfReference />);
+        fireEvent.click(await screen.findByLabelText('Self reference'));
+        expect(await screen.findAllByRole('option')).toHaveLength(5);
+        const titleInput = await screen.findByDisplayValue('War and Peace');
+        fireEvent.change(titleInput, {
+            target: { value: 'War and Peace 2' },
+        });
+        screen.getByLabelText('Save').click();
+        await screen.findByText('Proust', undefined, { timeout: 5000 });
+    });
 });

packages/ra-ui-materialui/src/input/ReferenceInput.stories.tsx

@@ -1,8 +1,8 @@
 import * as React from 'react';
 import { createMemoryHistory } from 'history';
-import { Admin, AdminContext } from 'react-admin';
+import { Admin, AdminContext, Datagrid, List, TextField } from 'react-admin';
 import { QueryClient } from 'react-query';
-import { Resource, Form, testDataProvider } from 'ra-core';
+import { Resource, Form, testDataProvider, useRedirect } from 'ra-core';
 import polyglotI18nProvider from 'ra-i18n-polyglot';
 import englishMessages from 'ra-language-english';
 import { Stack, Divider, Typography } from '@mui/material';
@@ -463,3 +463,47 @@ export const ErrorRadioButtonGroupInput = () => (
         />
     </Admin>
 );
+
+const AuthorList = () => (
+    <List>
+        <Datagrid>
+            <TextField source="first_name" />
+            <TextField source="last_name" />
+        </Datagrid>
+    </List>
+);
+
+const BookEditWithSelfReference = () => {
+    const redirect = useRedirect();
+    return (
+        <Edit
+            mutationMode="pessimistic"
+            mutationOptions={{
+                onSuccess: data => {
+                    // Redirecting to another page is an indirect way to make sure that
+                    // no errors happened during the update nor its side effects
+                    // (used by the jest tests)
+                    redirect('/authors');
+                },
+            }}
+        >
+            <SimpleForm>
+                <TextInput source="title" />
+                <ReferenceInput reference="books" source="self_reference" />
+            </SimpleForm>
+        </Edit>
+    );
+};
+
+export const SelfReference = ({ dataProvider = dataProviderWithAuthors }) => (
+    <Admin dataProvider={dataProvider} history={history}>
+        <Resource
+            name="authors"
+            recordRepresentation={record =>
+                `${record.first_name} ${record.last_name}`
+            }
+            list={AuthorList}
+        />
+        <Resource name="books" edit={BookEditWithSelfReference} />
+    </Admin>
+);