Automated rollback of commit 1d7bda4a78.

PiperOrigin-RevId: 519177322

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

@@ -358,7 +358,11 @@ bool HasRequiredFields(const Descriptor* descriptor);
 bool IsRealOneof(const FieldDescriptor* descriptor);
 
 inline bool HasHasbit(const FieldDescriptor* descriptor) {
-  return internal::cpp::HasHasbit(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();
 }
 
 // Whether generate classes expose public PARSER instances.

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

@@ -322,10 +322,8 @@ void ImmutableMessageFieldGenerator::GenerateBuilderMembers(
 
       "$name$Builder_.mergeFrom(value);\n",
 
-      "if ($name$_ != null) {\n"
-      "  $set_has_field_bit_builder$\n"
-      "  $on_changed$\n"
-      "}\n"
+      "$set_has_field_bit_builder$\n"
+      "$on_changed$\n"
       "return this;\n");
 
   // Message.Builder clearField()