packetbeat/route: fix test failure on Windows 2022

CHANGELOG-developer.next.asciidoc

@@ -98,6 +98,7 @@ The list below covers the major changes between 7.0.0-rc2 and main only.
 - Fix copy arguments for strict aligned architectures. {pull}36976[36976]
 - Fix panic when more than 32767 pipeline clients are active. {issue}38197[38197] {pull}38556[38556]
 - Skip flakey metrics test on windows in filebeat httpjson input. {issue}39676[39676] {pull}39678[39678]
+- Fix flakey test on Windows 2022 in packetbeat/route. {issue}39698[39698] {pull}39822[39822]
 
 ==== Added
 

packetbeat/route/route_test.go

@@ -32,7 +32,6 @@ import (
 )
 
 func TestDefault(t *testing.T) {
-	t.Skip("Flaky test: https://github.com/elastic/beats/issues/39698")
 	for _, family := range []int{syscall.AF_INET, syscall.AF_INET6} {
 		wantIface, wantIndex, wantErr := defaultRoute(family)
 		if wantErr != nil && wantErr != ErrNotFound {

packetbeat/route/route_windows_test.go

@@ -54,6 +54,9 @@ func defaultRoute(af int) (name string, index int, err error) {
 	for inTable := false; sc.Scan(); {
 		f := strings.Fields(sc.Text())
 		if len(f) == 0 {
+			if inTable {
+				break
+			}
 			continue
 		}
 		if !inTable {
@@ -94,6 +97,9 @@ func defaultRoute(af int) (name string, index int, err error) {
 	for inTable := false; sc.Scan(); {
 		f := fieldsN(sc.Text(), 5)
 		if len(f) == 0 {
+			if inTable {
+				break
+			}
 			continue
 		}
 		if !inTable {
@@ -152,6 +158,7 @@ func fieldsN(s string, n int) []string {
 	}
 	var f []string
 	for s != "" {
+		l := len(s)
 		for i, r := range s {
 			if unicode.IsSpace(r) {
 				f = append(f, s[:i])
@@ -165,7 +172,7 @@ func fieldsN(s string, n int) []string {
 				break
 			}
 		}
-		if len(f) == n-1 {
+		if len(f) == n-1 || len(s) == l {
 			break
 		}
 	}