allocate string for error description only if it really required

alextomaili · alextomaili · commit f71b9090aa17 · 2019-05-27T03:02:21.000+03:00
diff --git a/reflect_struct_decoder.go b/reflect_struct_decoder.go
@@ -530,8 +530,8 @@ func (decoder *generalStructDecoder) decodeOneField(ptr unsafe.Pointer, iter *It
 		}
 	}
 	if fieldDecoder == nil {
-		msg := "found unknown field: " + field
 		if decoder.disallowUnknownFields {
+			msg := "found unknown field: " + field
 			iter.ReportError("ReadObject", msg)
 		}
 		c := iter.nextToken()

Original file line number	Diff line number	Diff line change
`@@ -530,8 +530,8 @@ func (decoder generalStructDecoder) decodeOneField(ptr unsafe.Pointer, iter It`
`530`	`530`	`}`
`531`	`531`	`}`
`532`	`532`	`if fieldDecoder == nil {`
`533`		`- msg := "found unknown field: " + field`
`534`	`533`	`if decoder.disallowUnknownFields {`
	`534`	`+ msg := "found unknown field: " + field`
`535`	`535`	`iter.ReportError("ReadObject", msg)`
`536`	`536`	`}`
`537`	`537`	`c := iter.nextToken()`