Jens-G commented on code in PR #3414:
URL: https://github.com/apache/thrift/pull/3414#discussion_r3127313052
##########
compiler/cpp/src/thrift/generate/t_rs_generator.cc:
##########
@@ -1699,10 +1699,37 @@ void t_rs_generator::render_struct_sync_read(const
string& struct_name,
for (members_iter = members.begin(); members_iter != members.end();
++members_iter) {
t_field* tfield = (*members_iter);
+ t_type* resolved = get_true_type(tfield->get_type());
+ bool is_union_field = resolved->is_struct() &&
((t_struct*)resolved)->is_union();
f_gen_ << indent() << rust_safe_field_id(tfield->get_key()) << " => {"
<< '\n';
indent_up();
- render_type_sync_read("val", tfield->get_type());
- f_gen_ << indent() << struct_field_read_temp_variable(tfield) << " =
Some(val);" << '\n';
+ if (is_union_field) {
+ // Union fields: catch "received empty union" errors from unknown
+ // variants and treat them as None for forward compatibility.
+ // This matches how Java, Go, and Python Thrift handle unknown
+ // union fields -- they skip silently instead of failing.
+ //
+ // Use the resolved (non-Box) type for the method call since
+ // Box<T>::method() is not valid Rust syntax for turbofish.
+ string resolved_type = to_rust_type(resolved);
+ bool is_boxed_union = to_rust_type(tfield->get_type()) !=
resolved_type;
+ string read_call(resolved_type + "::read_from_in_protocol(i_prot)");
+ string val_expr = is_boxed_union ? "Box::new(val)" : "val";
+ f_gen_ << indent() << "match " << read_call << " {" << '\n';
+ indent_up();
+ f_gen_ << indent() << "Ok(val) => { " <<
struct_field_read_temp_variable(tfield) << " = Some(" << val_expr << "); }," <<
'\n';
+ f_gen_ << indent() << "Err(thrift::Error::Protocol(ref e)) if
e.message.contains(\"received empty union\") => {" << '\n';
Review Comment:
I would consider that a code smell. What about addinmg a dedicated
ProtocolErrorKind variant? Similar to ProtocolErrorKind::InvalidData for the
"empty union" case around line 1837.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
