From b6ec56bc26a89e9733390dd41fade5baace5a641 Mon Sep 17 00:00:00 2001 From: Romain Baugue Date: Wed, 1 May 2019 14:52:57 +0200 Subject: encoding/json: don't indirect pointers when decoding null MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The indirect method checked the type of the child when indirecting a pointer. If the current value is a pointer and we are decoding null, we can skip this entirely and return early, avoiding the whole descent. Fixes #31776 Change-Id: Ib8b2a2357572c41f56fceac59b5a858980f3f65e Reviewed-on: https://go-review.googlesource.com/c/go/+/174699 Run-TryBot: Daniel Martí TryBot-Result: Gobot Gobot Reviewed-by: Daniel Martí --- src/encoding/json/decode.go | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'src/encoding/json/decode.go') diff --git a/src/encoding/json/decode.go b/src/encoding/json/decode.go index 2b135f0da5..360fc69d04 100644 --- a/src/encoding/json/decode.go +++ b/src/encoding/json/decode.go @@ -416,8 +416,9 @@ func (d *decodeState) valueQuoted() interface{} { // indirect walks down v allocating pointers as needed, // until it gets to a non-pointer. -// if it encounters an Unmarshaler, indirect stops and returns that. -// if decodingNull is true, indirect stops at the last pointer so it can be set to nil. +// If it encounters an Unmarshaler, indirect stops and returns that. +// If decodingNull is true, indirect stops at the first settable pointer so it +// can be set to nil. func indirect(v reflect.Value, decodingNull bool) (Unmarshaler, encoding.TextUnmarshaler, reflect.Value) { // Issue #24153 indicates that it is generally not a guaranteed property // that you may round-trip a reflect.Value by calling Value.Addr().Elem() @@ -456,7 +457,7 @@ func indirect(v reflect.Value, decodingNull bool) (Unmarshaler, encoding.TextUnm break } - if v.Elem().Kind() != reflect.Ptr && decodingNull && v.CanSet() { + if decodingNull && v.CanSet() { break } -- cgit v1.3