interface argument in variadic function call

[mvertes]

The following program sample.go triggers an unexpected result

package main

type Option interface {
    apply()
}

func f(opts ...Option) {
    for _, opt := range opts {
        opt.apply()
    }
}

type T struct{}

func (t *T) apply() { println("in apply") }

func main() {
    opt := []Option{&T{}}
    f(opt[0], &T{}) // works
    f(opt...)       // fails
}

Expected result

$ go run ./sample.go
in apply
in apply
in apply

Got

$ yaegi ./sample.go
in apply
in apply
./sample.go:9:3: panic
./sample.go:20:2: panic
run: /Users/marc/yt/issue-1172-5.go:9:3: method not found: apply
goroutine 1 [running]:
runtime/debug.Stack(0x1, 0x140002faa00, 0x40)
	/Users/marc/sdk/go1.16.6/src/runtime/debug/stack.go:24 +0x88
github.com/traefik/yaegi/interp.(*Interpreter).eval.func1(0x1400023dbf0)
	/Users/marc/go/src/github.com/traefik/yaegi/interp/interp.go:505 +0x94
panic(0x1011fcbc0, 0x140001a3020)
	/Users/marc/sdk/go1.16.6/src/runtime/panic.go:965 +0x14c
github.com/traefik/yaegi/interp.runCfg.func1(0x140001d6d10, 0x140004c6300, 0x1400023d9c0)
	/Users/marc/go/src/github.com/traefik/yaegi/interp/run.go:185 +0x1e8
panic(0x1011fcbc0, 0x140001a3020)
	/Users/marc/sdk/go1.16.6/src/runtime/panic.go:965 +0x14c
github.com/traefik/yaegi/interp.runCfg.func1(0x140001d7130, 0x140001cfd00, 0x1400023d750)
	/Users/marc/go/src/github.com/traefik/yaegi/interp/run.go:185 +0x1e8
panic(0x1011fcbc0, 0x140001a3020)
	/Users/marc/sdk/go1.16.6/src/runtime/panic.go:965 +0x14c
github.com/traefik/yaegi/interp.getMethodByName.func1(0x140001d7130, 0x140002f0900)
	/Users/marc/go/src/github.com/traefik/yaegi/interp/run.go:1822 +0x614
github.com/traefik/yaegi/interp.runCfg(0x140001cfd00, 0x140001d7130)
	/Users/marc/go/src/github.com/traefik/yaegi/interp/run.go:191 +0x8c
github.com/traefik/yaegi/interp.call.func6(0x140001d6d10, 0x140001ccf80)
	/Users/marc/go/src/github.com/traefik/yaegi/interp/run.go:1283 +0xa28
github.com/traefik/yaegi/interp.runCfg(0x140004c6300, 0x140001d6d10)
	/Users/marc/go/src/github.com/traefik/yaegi/interp/run.go:191 +0x8c
github.com/traefik/yaegi/interp.(*Interpreter).run(0x1400037e000, 0x140004c5700, 0x140001d6a50)
	/Users/marc/go/src/github.com/traefik/yaegi/interp/run.go:122 +0x244
github.com/traefik/yaegi/interp.(*Interpreter).eval(0x1400037e000, 0x14000190600, 0xfc, 0x16f7237c0, 0x1e, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
	/Users/marc/go/src/github.com/traefik/yaegi/interp/interp.go:597 +0x5e8
github.com/traefik/yaegi/interp.(*Interpreter).EvalPath(0x1400037e000, 0x16f7237c0, 0x1e, 0x14000190500, 0xfc, 0x0, 0x0, 0x0)
	/Users/marc/go/src/github.com/traefik/yaegi/interp/interp.go:419 +0xc4
main.runFile(0x1400037e000, 0x16f7237c0, 0x1e, 0x0, 0x0, 0x0)
	/Users/marc/go/src/github.com/traefik/yaegi/cmd/yaegi/run.go:149 +0x84
main.run(0x140001b8010, 0x1, 0x1, 0x14000186180, 0x14000073ea8)
	/Users/marc/go/src/github.com/traefik/yaegi/cmd/yaegi/run.go:112 +0x830
main.main()
	/Users/marc/go/src/github.com/traefik/yaegi/cmd/yaegi/yaegi.go:144 +0x324

Yaegi Version

0.9.21

Additional Notes

related to #1172