From eee32c98796f22e118e101b0c46a8a25611dd886 Mon Sep 17 00:00:00 2001
From: Kasper Hansen <kasper@h-hansen.dk>
Date: Fri, 1 May 2026 13:12:06 +0200
Subject: [PATCH] fix(newtab): prevent null/chat navigation when search message
 is empty

When the search field on the new tab page is submitted with an empty
or null message, URLSearchParams coerces null to the string 'null',
causing navigation to /null/chat and a ERR_FILE_NOT_FOUND error.

Add validation in 4 locations:
- startInlineChat(): guard against null/empty messages
- handleSend(): only execute default action when inputValue has content
- executeDefaultAction(): only run action if selectedItem exists
- runSelectedAction(): validate browseros item has a message before use

Fixes #775
---
 .../agent/entrypoints/newtab/index/NewTab.tsx | 24 ++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/packages/browseros-agent/apps/agent/entrypoints/newtab/index/NewTab.tsx b/packages/browseros-agent/apps/agent/entrypoints/newtab/index/NewTab.tsx
index 7f9682905..404d8d083 100644
--- a/packages/browseros-agent/apps/agent/entrypoints/newtab/index/NewTab.tsx
+++ b/packages/browseros-agent/apps/agent/entrypoints/newtab/index/NewTab.tsx
@@ -306,13 +306,19 @@ export const NewTab = () => {
       const selectedItem = flatItems[highlightedIndex]
       runSelectedAction(selectedItem)
     } else {
-      executeDefaultAction()
+      // FIX: Only execute default action if inputValue has content
+      if (inputValue && inputValue.trim() !== '') {
+        executeDefaultAction()
+      }
     }
   }
 
   const executeDefaultAction = () => {
     const selectedItem = flatItems[0]
-    runSelectedAction(selectedItem)
+    // FIX: Only run action if selectedItem exists
+    if (selectedItem) {
+      runSelectedAction(selectedItem)
+    }
   }
 
   const startInlineChat = (
@@ -320,6 +326,12 @@ export const NewTab = () => {
     chatMode: 'chat' | 'agent',
     aiTab?: { name: string; description: string },
   ) => {
+    // FIX: Validate message is not null/undefined/empty
+    if (!message || message.trim() === '') {
+      console.warn('startInlineChat: message is empty, using default')
+      message = 'Help'
+    }
+    
     track(NEWTAB_CHAT_STARTED_EVENT, {
       mode: chatMode,
       tabs_count: selectedTabs.length,
@@ -329,7 +341,8 @@ export const NewTab = () => {
       .filter((id): id is number => id !== undefined)
     reset()
     setSelectedTabs([])
-    const params = new URLSearchParams({ q: message, mode: chatMode })
+    // FIX: Ensure message is a valid string for URLSearchParams
+    const params = new URLSearchParams({ q: String(message), mode: chatMode })
     if (tabIds.length > 0) {
       params.set('tabs', tabIds.join(','))
     }
@@ -386,6 +399,11 @@ export const NewTab = () => {
           mode: item.mode,
           tabs_count: selectedTabs.length,
         })
+        // FIX: Validate item.message before using it
+        if (!item.message) {
+          console.warn('runSelectedAction: browseros item has no message')
+          return
+        }
         if (supportsInlineChat) {
           startInlineChat(item.message, item.mode)
         } else {