From 56828e15b875b77db16f593784689003ee9ca7d2 Mon Sep 17 00:00:00 2001
From: Bonerush <2630234655@qq.com>
Date: Tue, 26 May 2026 15:42:09 +0800
Subject: [PATCH] fix: diff display edge cases for empty patches and hunks

- FileEditToolDiff: show "No changes to display" when patch is empty

- FileWriteToolDiff: guard against empty hunks array

- getPatchForDisplay: skip replace when old_string is empty
---
 src/components/FileEditToolDiff.tsx                      | 9 +++++++++
 .../FileWritePermissionRequest/FileWriteToolDiff.tsx     | 2 +-
 src/utils/diff.ts                                        | 3 +++
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/components/FileEditToolDiff.tsx b/src/components/FileEditToolDiff.tsx
index 71acf43389..b4ad695165 100644
--- a/src/components/FileEditToolDiff.tsx
+++ b/src/components/FileEditToolDiff.tsx
@@ -37,6 +37,15 @@ export function FileEditToolDiff(props: Props): React.ReactNode {
 function DiffBody({ promise, file_path }: { promise: Promise<DiffData>; file_path: string }): React.ReactNode {
   const { patch, firstLine, fileContent } = use(promise);
   const { columns } = useTerminalSize();
+
+  if (patch.length === 0) {
+    return (
+      <DiffFrame>
+        <Text dimColor>No changes to display</Text>
+      </DiffFrame>
+    );
+  }
+
   return (
     <DiffFrame>
       <StructuredDiffList
diff --git a/src/components/permissions/FileWritePermissionRequest/FileWriteToolDiff.tsx b/src/components/permissions/FileWritePermissionRequest/FileWriteToolDiff.tsx
index 54b1e1d3ff..25ec9354c3 100644
--- a/src/components/permissions/FileWritePermissionRequest/FileWriteToolDiff.tsx
+++ b/src/components/permissions/FileWritePermissionRequest/FileWriteToolDiff.tsx
@@ -46,7 +46,7 @@ export function FileWriteToolDiff({ file_path, content, fileExists, oldContent }
         borderRight={false}
         paddingX={paddingX}
       >
-        {hunks ? (
+        {hunks && hunks.length > 0 ? (
           intersperse(
             hunks.map(_ => (
               <StructuredDiff
diff --git a/src/utils/diff.ts b/src/utils/diff.ts
index 630a00d7d9..b05caf6761 100644
--- a/src/utils/diff.ts
+++ b/src/utils/diff.ts
@@ -153,6 +153,9 @@ export function getPatchForDisplay({
         convertLeadingTabsToSpaces(new_string),
       )
 
+      if (escapedOldString === '') {
+        return escapedNewString
+      }
       if (replace_all) {
         return p.replaceAll(escapedOldString, () => escapedNewString)
       } else {