Automated rollback of commit 3e188b7c04.

PiperOrigin-RevId: 542744002

src/google/protobuf/compiler/java/helpers.h

@@ -358,11 +358,7 @@ bool HasRequiredFields(const Descriptor* descriptor);
 bool IsRealOneof(const FieldDescriptor* descriptor);
 
 inline bool HasHasbit(const FieldDescriptor* descriptor) {
-  // TODO(b/241441075) Replace this with internal::cpp::HasHasbit once Elysium
-  // unblocks this change.
-  return (FieldDescriptorLegacy(descriptor).has_optional_keyword() ||
-          descriptor->is_required()) &&
-         !descriptor->options().weak();
+  return internal::cpp::HasHasbit(descriptor);
 }
 
 // Whether generate classes expose public PARSER instances.

src/google/protobuf/compiler/java/message_field.cc

@@ -326,8 +326,10 @@ void ImmutableMessageFieldGenerator::GenerateBuilderMembers(
 
       "$name$Builder_.mergeFrom(value);\n",
 
-      "$set_has_field_bit_builder$\n"
-      "$on_changed$\n"
+      "if ($name$_ != null) {\n"
+      "  $set_has_field_bit_builder$\n"
+      "  $on_changed$\n"
+      "}\n"
       "return this;\n",
       Semantic::kSet);