From 2e728edfdadd50b0201e7f1640c2c1a59552c38c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Guillermo=20D=C3=ADaz?= <guillermo@otherplane.com>
Date: Tue, 13 Aug 2024 16:54:17 +0200
Subject: [PATCH] fix(wrb): readResponseResult must return unsuccessful result
 if reponse cbor value is empty

---
 .../core/customs/WitnetRequestBoardBypassV20.sol | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/contracts/impls/core/customs/WitnetRequestBoardBypassV20.sol b/contracts/impls/core/customs/WitnetRequestBoardBypassV20.sol
index c6976df6..d336db6a 100644
--- a/contracts/impls/core/customs/WitnetRequestBoardBypassV20.sol
+++ b/contracts/impls/core/customs/WitnetRequestBoardBypassV20.sol
@@ -653,7 +653,21 @@ contract WitnetRequestBoardBypassV20
         legacyFallback(_queryId) 
         returns (Witnet.Result memory)
     {
-        return Witnet.resultFromCborBytes(__response(_queryId).cborBytes);
+        if (__response(_queryId).cborBytes.length > 0) {
+            return Witnet.resultFromCborBytes(__response(_queryId).cborBytes);
+        } else {
+            return Witnet.Result({
+                success: false,
+                value: WitnetCBOR.CBOR({
+                    buffer: WitnetBuffer.Buffer(hex"", 0),
+                    initialByte: 0,
+                    majorType: 0,
+                    additionalInformation: 0,
+                    len: 0,
+                    tag: 0
+                })
+            });
+        }
     }
 
     /// Retrieves the timestamp in which the result to the referred query was solved by the Witnet DON.