# --- T2-COPYRIGHT-BEGIN ---
# t2/package/*/firefox/hotfix-ia64-uniffi-handle.patch
# Copyright (C) 2026 The T2 SDE Project
# SPDX-License-Identifier: GPL-2.0 or patched project license
# --- T2-COPYRIGHT-END ---

--- firefox-152.0.5/toolkit/components/uniffi-js/Callbacks.cpp.vanilla
+++ firefox-152.0.5/toolkit/components/uniffi-js/Callbacks.cpp
@@ -40,7 +145,9 @@
   // Finally, we always set the lowest bit on the handle.  This allows UniFFI to
   // tell if trait interface handles came from JS or Rust.
   HandleRefCount* handlePointer = new HandleRefCount(1);
-  return reinterpret_cast<uint64_t>(handlePointer) | 1;
+  // Convert via uintptr_t: a direct pointer-to-uint64_t cast sign-extends on
+  // 32-bit targets, producing handles above 2^53 for high heap addresses.
+  return uint64_t(reinterpret_cast<uintptr_t>(handlePointer)) | 1;
 }
 
 uint32_t CallbackHandleAddRef(uint64_t aHandle) {