treat context cancellation as terminal error

pschultz · pschultz · commit ef3fff0fd93b · 2022-02-03T14:16:34.000+01:00
diff --git a/resolver.go b/resolver.go
@@ -449,7 +449,14 @@ func (r *resolver) discoverRootServers(ctx context.Context, trace *Trace) ([]str
 }
 
 func isTerminal(resp *dns.Msg, err error) bool {
-	return errors.Is(err, ErrCircular)
+	switch {
+	case errors.Is(err, ErrCircular),
+		errors.Is(err, context.Canceled),
+		errors.Is(err, context.DeadlineExceeded):
+		return true
+	default:
+		return false
+	}
 }
 
 func (r *resolver) referrals(m *dns.Msg) (ips, names []string) {

Original file line number	Diff line number	Diff line change
`@@ -449,7 +449,14 @@ func (r resolver) discoverRootServers(ctx context.Context, trace Trace) ([]str`
`449`	`449`	`}`
`450`	`450`
`451`	`451`	`func isTerminal(resp *dns.Msg, err error) bool {`
`452`		`- return errors.Is(err, ErrCircular)`
	`452`	`+ switch {`
	`453`	`+ case errors.Is(err, ErrCircular),`
	`454`	`+ errors.Is(err, context.Canceled),`
	`455`	`+ errors.Is(err, context.DeadlineExceeded):`
	`456`	`+ return true`
	`457`	`+ default:`
	`458`	`+ return false`
	`459`	`+ }`
`453`	`460`	`}`
`454`	`461`
`455`	`462`	`func (r resolver) referrals(m dns.Msg) (ips, names []string) {`