From 0933c9f8d5685c696684a02aca413faa2dc0ce57 Mon Sep 17 00:00:00 2001
From: tserg <8017125+tserg@users.noreply.github.com>
Date: Sat, 30 Sep 2023 10:43:57 +0800
Subject: [PATCH] set max len if not annotated

---
 vyper/builtins/functions.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/vyper/builtins/functions.py b/vyper/builtins/functions.py
index 7a128567a0..d71592ee1f 100644
--- a/vyper/builtins/functions.py
+++ b/vyper/builtins/functions.py
@@ -377,7 +377,11 @@ def build_IR(self, expr, args, kwargs, context):
 
             # Get returntype string or bytes
             dst_typ = expr._metadata.get("type")
-            assert isinstance(dst_typ, _BytestringT) or is_bytes32
+            assert isinstance(dst_typ, _BytestringT)
+
+            # set the length of the return type if it was not defined in annotation
+            if dst_typ.length == 0:
+                dst_typ.set_length(dst_maxlen)
 
             # allocate a buffer for the return value
             buf = context.new_internal_variable(BytesT(buflen))