From abe69ac29e648f4a6c6c98ba20ad626858058ac5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E9=AB=98=E8=89=B3=E5=85=B5?= <yanbing.gao@aliyun.com>
Date: Mon, 28 Sep 2026 10:36:25 +0800
Subject: [PATCH] fix: preserve zero-valued overflow indicators

---
 src/Overflow.tsx             | 21 ++++++++++++---------
 tests/renderability.spec.tsx | 24 ++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 9 deletions(-)
 create mode 100644 tests/renderability.spec.tsx

diff --git a/src/Overflow.tsx b/src/Overflow.tsx
index ffa2bc8..18de929 100644
--- a/src/Overflow.tsx
+++ b/src/Overflow.tsx
@@ -16,8 +16,10 @@ export { OverflowContext } from './context';
 
 export type { ComponentType } from './RawItem';
 
-export interface OverflowProps<ItemType>
-  extends Omit<React.HTMLAttributes<any>, 'prefix'> {
+export interface OverflowProps<ItemType> extends Omit<
+  React.HTMLAttributes<any>,
+  'prefix'
+> {
   prefixCls?: string;
   className?: string;
   style?: React.CSSProperties;
@@ -30,8 +32,7 @@ export interface OverflowProps<ItemType>
   renderRawItem?: (item: ItemType, index: number) => React.ReactElement;
   maxCount?: number | typeof RESPONSIVE | typeof INVALIDATE;
   renderRest?:
-    | React.ReactNode
-    | ((omittedItems: ItemType[]) => React.ReactNode);
+    React.ReactNode | ((omittedItems: ItemType[]) => React.ReactNode);
   /** @private Do not use in your production. Render raw node that need wrap Item by developer self */
   renderRawRest?: (omittedItems: ItemType[]) => React.ReactElement;
   prefix?: React.ReactNode;
@@ -380,7 +381,9 @@ function Overflow<ItemType = any>(
     display: displayRest,
   };
 
-  const mergedRenderRest = renderRest || defaultRenderRest;
+  const mergedRenderRest = isReactRenderable(renderRest)
+    ? renderRest
+    : defaultRenderRest;
 
   const restNode = renderRawRest ? (
     <OverflowContext.Provider
@@ -465,13 +468,13 @@ type FilledOverflowType = ForwardOverflowType & {
   INVALIDATE: typeof INVALIDATE;
 };
 
-((ForwardOverflow as unknown) as FilledOverflowType).Item = RawItem;
-((ForwardOverflow as unknown) as FilledOverflowType).RESPONSIVE = RESPONSIVE;
-((ForwardOverflow as unknown) as FilledOverflowType).INVALIDATE = INVALIDATE;
+(ForwardOverflow as unknown as FilledOverflowType).Item = RawItem;
+(ForwardOverflow as unknown as FilledOverflowType).RESPONSIVE = RESPONSIVE;
+(ForwardOverflow as unknown as FilledOverflowType).INVALIDATE = INVALIDATE;
 
 if (process.env.NODE_ENV !== 'production') {
   ForwardOverflow.displayName = 'Overflow';
 }
 
 // Convert to generic type
-export default (ForwardOverflow as unknown) as FilledOverflowType;
+export default ForwardOverflow as unknown as FilledOverflowType;
diff --git a/tests/renderability.spec.tsx b/tests/renderability.spec.tsx
new file mode 100644
index 0000000..ce4191c
--- /dev/null
+++ b/tests/renderability.spec.tsx
@@ -0,0 +1,24 @@
+import React from 'react';
+import { render } from '@testing-library/react';
+import Overflow from '../src';
+
+it.each([0, () => 0])('renders zero rest content %s', renderRest => {
+  const { container } = render(
+    <Overflow data={['A', 'B']} maxCount={1} renderRest={renderRest} />,
+  );
+  expect(container.querySelector('.rc-overflow-item-rest').textContent).toBe(
+    '0',
+  );
+});
+
+it.each([false, null, undefined, ''])(
+  'keeps the default rest for %s',
+  renderRest => {
+    const { container } = render(
+      <Overflow data={['A', 'B']} maxCount={1} renderRest={renderRest} />,
+    );
+    expect(container.querySelector('.rc-overflow-item-rest').textContent).toBe(
+      '+ 1 ...',
+    );
+  },
+);