fix(ComboBox): Skip blur commits for read-only fields

Read-only ComboBoxes cannot change their selection or input, so skip committing a value when focus leaves the field.

AI-assisted: Claude Code

Author: florianaltendorfer

packages/react-aria-components/test/ComboBox.test.js

@@ -500,6 +500,27 @@ describe('ComboBox', () => {
     expect(queryByRole('listbox')).not.toBeInTheDocument();
   });
 
+  it('should not fire change events on blur when isReadOnly', async () => {
+    let onChange = jest.fn();
+    let onSelectionChange = jest.fn();
+    let {getByRole} = render(
+      <TestComboBox
+        isReadOnly
+        value="4"
+        inputValue="Finland"
+        onChange={onChange}
+        onSelectionChange={onSelectionChange}
+      />
+    );
+
+    let input = getByRole('combobox');
+    await user.click(input);
+    await user.tab();
+
+    expect(onChange).not.toHaveBeenCalled();
+    expect(onSelectionChange).not.toHaveBeenCalled();
+  });
+
   it('should support virtualizer', async () => {
     let items = [];
     for (let i = 0; i < 50; i++) {

packages/react-stately/src/combobox/useComboBoxState.ts

@@ -602,7 +602,7 @@ export function useComboBoxState<T, M extends SelectionMode = 'single'>(
         open(null, 'focus');
       }
     } else {
-      if (shouldCloseOnBlur) {
+      if (shouldCloseOnBlur && !props.isReadOnly) {
         commitValue();
       }