encoding/xml: Unmarshal improper behavior with non-string types and empty tags

[cmazakas]

Please answer these questions before submitting your issue. Thanks!

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

go version go1.8.3 darwin/amd64

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

GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/exbigboss/go"
GORACE=""
GOROOT="/usr/local/go"
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/f2/331cyngd4nxb24p47_sb9zx40000gn/T/go-build190222818=/tmp/go-build -gno-record-gcc-switches -fno-common"
CXX="clang++"
CGO_ENABLED="1"
PKG_CONFIG="pkg-config"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"

What did you do?

https://play.golang.org/p/3y8tab_Ipn

If possible, provide a recipe for reproducing the error.
A complete runnable program is good.
A link on play.golang.org is best.

What did you expect to see?

I expected that Value would default to false (the zero value for the type)

What did you see instead?

I received a parsing error

[namusyaka]

This was fixed by 0a0186f, I think.

@LeonineKing1199 Could you confirm that?

[cmazakas]

I think I'm just using outdated versions of Go then. I checked the git commit you posted and it looks like it was intended for Go 1.9. I'm using 1.8 on both my Mac and Windows machines and it's equally broken in both places.

I circumvented the issue by creating a quick little nilable package.

[ALTree]

go1.9rc2 output is &{Value:false Name:Big Boss}, so it appears that this is fixed.

Closing this issue, since there's noting more to do.

[cmazakas]

I know the issue is closed but could the docs be updated until the stable release is 1.9?

It'd be useful if the docs also contained that information for the sake of legacy code. How about something like this,

Pre-1.9 unmarshaling will return a parsing error in the case of empty tags for non-string unmarshalling targets.

For example:
/ * code sample goes here /*

will return the error:  sample error

Go 1.9 and beyond will instead assign use the default constructor. Er, I mean zero value.

[ALTree]

I know the issue is closed but could the docs be updated until the stable release is 1.9

go1.9 should be released in a few days, so I don't think it's worth it.

Also updating the go1.8 website would require the release of a new minor (1.8.4), and there's almost no chance of that happening, since the website will be re-deployed for go1.9 very soon (and this issue won't be there, since it was fixed for go1.9).