From aa68739fa716d53bc278484410b78070bdf579b0 Mon Sep 17 00:00:00 2001
From: Joshua Haberman <haberman@google.com>
Date: Wed, 18 Jan 2023 10:46:16 -0800
Subject: [PATCH] Fixed a bug with field numbers >255 in a oneof.

The compiler should not assert-fail in this case, it should merely decline to emit a fast parser for that field.

PiperOrigin-RevId: 502919928
---
 upbc/protoc-gen-upb.cc | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/upbc/protoc-gen-upb.cc b/upbc/protoc-gen-upb.cc
index 4e0e67a96f..5a8308a373 100644
--- a/upbc/protoc-gen-upb.cc
+++ b/upbc/protoc-gen-upb.cc
@@ -1107,8 +1107,7 @@ bool TryFillTableEntry(const DefPoolPair& pools, upb::FieldDefPtr field,
   }
   if (field.real_containing_oneof()) {
     uint64_t case_offset = ~mt_f->presence;
-    if (case_offset > 0xffff) return false;
-    assert(field.number() < 256);
+    if (case_offset > 0xffff || field.number() > 0xff) return false;
     data |= field.number() << 24;
     data |= case_offset << 32;
   } else {