False-positive with a graceful shutdown

[AlekSi]

Simplified example:

// Run runs server until ctx is canceled, then stops it gracefully and exits.
func RunHandler(ctx context.Context) {
	s := http.Server{
		BaseContext: func(_ net.Listener) context.Context {
			return ctx
		},
	}

	go s.ListenAndServe()
	<-ctx.Done()

	// use new context for cancelation
	stopCtx, stopCancel := context.WithTimeout(context.Background(), time.Second) 
	defer stopCancel()
	s.Shutdown(stopCtx)

	s.Close()
}

stopCtx can't be inherited from ctx as the later is already canceled.

Maybe this linter can detect that <-ctx.Done() was already called by this point?

[nawa]

The same I faced with. It is more abstract example

package main

import (
	"context"
)

func main() {
	doSmth(context.Background())
}

func doSmth(ctx context.Context) {
	doSmth2(ctx)

	// I want to use context.Background() here
	ctx2, ctx2Cancel := context.WithCancel(context.Background())
	defer ctx2Cancel()

	doSmth2(ctx2)
}

func doSmth2(ctx context.Context) {
	_ = ctx
}

main.go:17:9: Non-inherited new context, use function like `context.WithXXX` instead (contextcheck)
        doSmth2(ctx2)

The issue occurs when context is provided into the function but I want to use another context instance intentionally. For example graceful shutdown should be done with Background context.

And currently there is no way to avoid this error from the linter

[kkHAIKE]

this case can write func like this to pass

func NoInheritCancel(_ context.Context) (context.Context,context.CancelFunc) {
  return context.WithCancel(context.Background())
}