From 2808ccc149a7ad3e18c8b221f424555193fc3d14 Mon Sep 17 00:00:00 2001
From: Mark Haslinghuis <mark@numloq.nl>
Date: Wed, 15 Oct 2025 00:05:50 +0200
Subject: [PATCH] Fix MSP callback on crc error

---
 src/js/msp/MSPHelper.js | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/src/js/msp/MSPHelper.js b/src/js/msp/MSPHelper.js
index be31840a98..f175d04950 100644
--- a/src/js/msp/MSPHelper.js
+++ b/src/js/msp/MSPHelper.js
@@ -1779,13 +1779,17 @@ MspHelper.prototype.process_data = function (dataHandler) {
 
             // remove object from array
             dataHandler.callbacks.splice(i, 1);
-            if (!crcError) {
-                // fire callback
-                if (callback) {
-                    callback({ command: code, data: data, length: data.byteLength, crcError: crcError });
+            // Always invoke callback and pass crcError flag. Callbacks expect to
+            // receive the original DataView so they can choose how to handle CRC
+            // errors; don't replace the data with null here to avoid breaking
+            // existing consumers that dereference response.data before checking
+            // crcError.
+            if (callback) {
+                try {
+                    callback({ command: code, data: data, length: data ? data.byteLength : 0, crcError: crcError });
+                } catch (e) {
+                    console.error(`callback for code ${code} threw:`, e);
                 }
-            } else {
-                console.warn(`code: ${code} - crc failed. No callback`);
             }
         }
     }