From c44f05312a8956426ae527df28c47cb4f6bc5cd7 Mon Sep 17 00:00:00 2001
From: kbullinger <kristopher.bullinger@fox.com>
Date: Wed, 2 Oct 2024 17:30:09 -0400
Subject: [PATCH] add support for group in oneof; add field_number to
 unknown_fields instead of tag

---
 protobuf-codegen/src/gen/field/mod.rs | 41 +++++++++++++++++++++++----
 protobuf-codegen/src/gen/oneof.rs     | 15 +++++++++-
 protobuf/src/rt/unknown_or_group.rs   |  2 +-
 3 files changed, 50 insertions(+), 8 deletions(-)

diff --git a/protobuf-codegen/src/gen/field/mod.rs b/protobuf-codegen/src/gen/field/mod.rs
index 9ab9270b4..e657ddd58 100644
--- a/protobuf-codegen/src/gen/field/mod.rs
+++ b/protobuf-codegen/src/gen/field/mod.rs
@@ -970,13 +970,42 @@ impl<'a> FieldGen<'a> {
             } else {
                 typed
             };
+            let variant_path = o.variant_path(&self.proto_field.message.scope.rust_path_to_file());
+            if o.elem.proto_type() == Type::TYPE_GROUP {
+                let proto_path = protobuf_crate_path(&self.customize);
+                w.write_line(&format!(
+                    "let end_tag = {proto_path}::rt::set_wire_type_to_end_group(tag);"
+                ));
+                let value_type = &self
+                    .elem()
+                    .rust_storage_elem_type(
+                        &self
+                            .proto_field
+                            .message
+                            .scope
+                            .file_and_mod(self.customize.clone()),
+                    )
+                    .to_code(&self.customize);
 
-            w.write_line(&format!(
-                "self.{} = ::std::option::Option::Some({}({}));",
-                o.oneof_field_name,
-                o.variant_path(&self.proto_field.message.scope.rust_path_to_file()),
-                maybe_boxed.value
-            ));
+                w.write_line(&format!(
+                    "let mut {} = {}::default();",
+                    o.oneof_field_name, value_type,
+                ));
+                w.write_line(&format!(
+                    "{}.merge_delimited(is, end_tag)?;",
+                    o.oneof_field_name,
+                ));
+
+                w.write_line(&format!(
+                    "self.{} = ::std::option::Option::Some({}({}));",
+                    o.oneof_field_name, variant_path, o.oneof_field_name,
+                ));
+            } else {
+                w.write_line(&format!(
+                    "self.{} = ::std::option::Option::Some({}({}));",
+                    o.oneof_field_name, variant_path, maybe_boxed.value
+                ));
+            }
         })
     }
 
diff --git a/protobuf-codegen/src/gen/oneof.rs b/protobuf-codegen/src/gen/oneof.rs
index e1bd33901..73b217627 100644
--- a/protobuf-codegen/src/gen/oneof.rs
+++ b/protobuf-codegen/src/gen/oneof.rs
@@ -223,6 +223,19 @@ impl<'a> OneofGen<'a> {
             .collect()
     }
 
+    pub fn variants(&'a self) -> impl Iterator<Item = OneofVariantGen<'a>> {
+        self.oneof.variants().into_iter().map(|v| {
+            let field = self
+                .message
+                .fields
+                .iter()
+                .filter(|f| f.proto_field.name() == v.field.name())
+                .next()
+                .expect(&format!("field not found by name: {}", v.field.name()));
+            OneofVariantGen::parse(self, v, field, self.message.root_scope)
+        })
+    }
+
     pub fn full_storage_type(&self) -> RustType {
         RustType::Option(Box::new(RustType::Oneof(
             self.type_name_relative(
@@ -262,7 +275,7 @@ impl<'a> OneofGen<'a> {
         }
         write_protoc_insertion_point_for_oneof(w, &self.customize.for_elem, &self.oneof.oneof);
         w.pub_enum(&self.oneof.rust_name().ident.to_string(), |w| {
-            for variant in self.variants_except_group() {
+            for variant in self.variants() {
                 write_protoc_insertion_point_for_oneof_field(
                     w,
                     &self.customize.for_children,
diff --git a/protobuf/src/rt/unknown_or_group.rs b/protobuf/src/rt/unknown_or_group.rs
index cf9d35f00..e43ae9721 100644
--- a/protobuf/src/rt/unknown_or_group.rs
+++ b/protobuf/src/rt/unknown_or_group.rs
@@ -76,7 +76,7 @@ pub fn read_unknown(
 ) -> crate::Result<()> {
     let (field_number, wire_type) = Tag::new(tag)?.unpack();
     let unknown = is.read_unknown_with_tag_unpacked(field_number, wire_type)?;
-    unknown_fields.add_value(tag, unknown);
+    unknown_fields.add_value(field_number, unknown);
     Ok(())
 }