From 28b9e7c7b83845c35fe46c37e8ed8e9022b4634e Mon Sep 17 00:00:00 2001
From: Tony <68118705+Legend-Master@users.noreply.github.com>
Date: Tue, 28 Oct 2025 18:07:50 +0800
Subject: [PATCH] fix: throw on custom protocol IPC fails (#14377)

---
 .changes/run-callback-after-catch.md |  5 +++++
 crates/tauri/scripts/ipc-protocol.js | 29 +++++++++++++++-------------
 2 files changed, 21 insertions(+), 13 deletions(-)
 create mode 100644 .changes/run-callback-after-catch.md

diff --git a/.changes/run-callback-after-catch.md b/.changes/run-callback-after-catch.md
new file mode 100644
index 000000000..9eefa9493
--- /dev/null
+++ b/.changes/run-callback-after-catch.md
@@ -0,0 +1,5 @@
+---
+tauri: patch:bug
+---
+
+Fix `undefined is not an object (evaluating '[callbackId, data]')` error on custom protocol IPC fails
diff --git a/crates/tauri/scripts/ipc-protocol.js b/crates/tauri/scripts/ipc-protocol.js
index 7f8f0e29a..9ca244053 100644
--- a/crates/tauri/scripts/ipc-protocol.js
+++ b/crates/tauri/scripts/ipc-protocol.js
@@ -52,19 +52,21 @@
               return response.arrayBuffer().then((r) => [callbackId, r])
           }
         })
-        .catch((e) => {
-          console.warn(
-            'IPC custom protocol failed, Tauri will now use the postMessage interface instead',
-            e
-          )
-          // failed to use the custom protocol IPC (either the webview blocked a custom protocol or it was a CSP error)
-          // so we need to fallback to the postMessage interface
-          customProtocolIpcFailed = true
-          sendIpcMessage(message)
-        })
-        .then(([callbackId, data]) => {
-          window.__TAURI_INTERNALS__.runCallback(callbackId, data)
-        })
+        .then(
+          ([callbackId, data]) => {
+            window.__TAURI_INTERNALS__.runCallback(callbackId, data)
+          },
+          (e) => {
+            console.warn(
+              'IPC custom protocol failed, Tauri will now use the postMessage interface instead',
+              e
+            )
+            // failed to use the custom protocol IPC (either the webview blocked a custom protocol or it was a CSP error)
+            // so we need to fallback to the postMessage interface
+            customProtocolIpcFailed = true
+            sendIpcMessage(message)
+          }
+        )
     } else {
       // otherwise use the postMessage interface
       const { data } = processIpcMessage({
@@ -78,6 +80,7 @@
         payload,
         __TAURI_INVOKE_KEY__
       })
+      // `window.ipc.postMessage` came from `tauri-runtime-wry` > `wry` [`with_ipc_handler`](https://github.com/tauri-apps/wry/blob/a0403b9e2f1ff9d73be7dce1184f058afcaa1d82/src/lib.rs#L1130)
       window.ipc.postMessage(data)
     }
   }