From 2c5136b7944a1447854d04470c2093d40a1bacf4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Piotr=20Miko=C5=82ajczyk?= <piomiko41@gmail.com>
Date: Wed, 6 May 2026 13:32:46 +0200
Subject: [PATCH 1/2] Use errors.As

---
 rpc/json.go | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/rpc/json.go b/rpc/json.go
index fcd801fc95..3e116be8c5 100644
--- a/rpc/json.go
+++ b/rpc/json.go
@@ -126,12 +126,12 @@ func errorMessage(err error) *jsonrpcMessage {
 		Code:    errcodeDefault,
 		Message: err.Error(),
 	}}
-	ec, ok := err.(Error)
-	if ok {
+	var ec Error
+	if errors.As(err, &ec) {
 		msg.Error.Code = ec.ErrorCode()
 	}
-	de, ok := err.(DataError)
-	if ok {
+	var de DataError
+	if errors.As(err, &de) {
 		msg.Error.Data = de.ErrorData()
 	}
 	return msg

From c471e3c571b2329d0b05f96656d1578fe51dba95 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Piotr=20Miko=C5=82ajczyk?= <piomiko41@gmail.com>
Date: Wed, 6 May 2026 14:49:34 +0200
Subject: [PATCH 2/2] Take data from the same object

---
 rpc/json.go | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/rpc/json.go b/rpc/json.go
index 3e116be8c5..e661f6aad2 100644
--- a/rpc/json.go
+++ b/rpc/json.go
@@ -126,12 +126,13 @@ func errorMessage(err error) *jsonrpcMessage {
 		Code:    errcodeDefault,
 		Message: err.Error(),
 	}}
-	var ec Error
-	if errors.As(err, &ec) {
-		msg.Error.Code = ec.ErrorCode()
+	var rpcError Error
+	if errors.As(err, &rpcError) {
+		msg.Error.Code = rpcError.ErrorCode()
 	}
-	var de DataError
-	if errors.As(err, &de) {
+	// Type assert on rpcError to ensure that both code and data come from the same error object.
+	de, ok := rpcError.(DataError)
+	if ok {
 		msg.Error.Data = de.ErrorData()
 	}
 	return msg