fix(log): custom marshaller produce invalid data (#17532)

log/CHANGELOG.md

@@ -22,6 +22,10 @@ Each entry must include the Github issue reference in the following format:
 
 ## [Unreleased]
 
+## [v1.2.1](https://github.com/cosmos/cosmos-sdk/releases/tag/log/v1.2.1) - 2023-08-25
+
+* [#17532](https://github.com/cosmos/cosmos-sdk/pull/17532) Proper marshalling of `fmt.Stringer` (follow-up of [#17205](https://github.com/cosmos/cosmos-sdk/pull/17205)).
+
 ## [v1.2.0](https://github.com/cosmos/cosmos-sdk/releases/tag/log/v1.2.0) - 2023-07-31
 
 * [#17194](https://github.com/cosmos/cosmos-sdk/pull/17194) Avoid repeating parse log level in `ParseLogLevel`.

log/logger.go

@@ -19,7 +19,7 @@ func init() {
 		case encoding.TextMarshaler:
 			return json.Marshal(i)
 		case fmt.Stringer:
-			return fmt.Appendf([]byte("\""), "%s%s", v.String(), "\""), nil
+			return json.Marshal(v.String())
 		default:
 			return json.Marshal(i)
 		}