json.Marshal ignores all fields exept embedded struct of type json.RawMessage

[sirbralex]

What version of Go are you using (go version)?

$ go version
go version go1.12.1 windows/amd64

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
set GOARCH=amd64
set GOBIN=
set GOCACHE=C:\Users\Aleksandr\AppData\Local\go-build
set GOEXE=.exe
set GOFLAGS=
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOOS=windows
set GOPATH=D:\GoProjects
set GOPROXY=
set GORACE=
set GOROOT=D:\Program Files\Go
set GOTMPDIR=
set GOTOOLDIR=D:\Program Files\Go\pkg\tool\windows_amd64
set GCCGO=gccgo
set CC=gcc
set CXX=g++
set CGO_ENABLED=1
set GOMOD=
set CGO_CFLAGS=-g -O2
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-g -O2
set CGO_FFLAGS=-g -O2
set CGO_LDFLAGS=-g -O2
set PKG_CONFIG=pkg-config
set GOGCCFLAGS=-m64 -mthreads -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=C:\Users\ALEKSA~1\AppData\Local\Temp\go-build286887446=/tmp/go-build -gno-record-gcc-switches

What did you do?

https://play.golang.org/p/5q8nGlLBDVy

What did you expect to see?

{"Title":"Programming in Go","Name":"Caleb Doxsey","Price":"20$"}

What did you see instead?

{"Price":"20$"}

[fraenkel]

@sirbralex json.Marshal is invoking the MarshalJson promoted via the embedded json.RawMessage.

You can read more here, https://golang.org/ref/spec#Struct_types

[dsnet]

This is an unfortunate gotcha of embedding in Go and there's not much that can be done to encoding/json. Addressing this requires some level of language change.

See #30148 (for related issue for json) and #22013 (for related issue about embedding in general).