Return false when C++ protos have different DescriptorPools.

PiperOrigin-RevId: 486118277

Author: laramiel

pybind11_protobuf/proto_cast_util.cc

@@ -584,7 +584,13 @@ absl::optional<std::string> PyProtoDescriptorName(py::handle py_proto) {
 
 bool PyProtoIsCompatible(py::handle py_proto, const Descriptor* descriptor) {
   assert(PyGILState_Check());
-  assert(descriptor->file()->pool() == DescriptorPool::generated_pool());
+  if (descriptor->file()->pool() != DescriptorPool::generated_pool()) {
+    /// This indicates that the C++ descriptor does not come from the C++
+    /// DescriptorPool. This may happen if the C++ code has the same proto
+    /// in different descriptor pools, perhaps from different shared objects,
+    /// and could be result in undefined behavior.
+    return false;
+  }
 
   auto py_descriptor = ResolveAttrs(py_proto, {"DESCRIPTOR"});
   if (!py_descriptor) {