Sub() ignores variables set with BindEnv/AutomaticEnv

[lucasvo]

The following example fails because Sub() because variables overwritten in env are ignored.

grandParent:
    parent:
        child: bar

package main

import (
	"fmt"
	"github.com/spf13/viper"
	"os"
	"strings"
)

var v *viper.Viper

func main() {
	os.Setenv("GRANDPARENT_PARENT_CHILD", "foo")
	v = viper.New()
	v.SetConfigType("yaml")
	v.AutomaticEnv()
	v.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
	f, _ := os.Open("test.yaml")
	v.ReadConfig(f)
	sub := v.Sub("grandParent.parent")
	fmt.Println("Direct", v.GetString("grandParent.parent.child"))
	fmt.Println("Sub", sub.GetString("child"))
	if sub.GetString("child") != v.GetString("grandParent.parent.child") {
		panic("sub ignores os.environ")
	}
}

The output of the program is:

Direct foo
Sub bar
panic: sub ignores os.environ
[...]

[lucasvo]

Related to: #307

[vail130]

Ran into this issue, which took a couple hours of debugging to discover. I'd love to see some explicit documentation about this limitation, if not a fix.

[lucasvo]

@spf13 would be awesome to get #508 merged! I am sure @vail130 and I are not the only ones here...

[guyisra]

any updates on this?