net: add unit test for empty nsswitch on linux

Add testcase for ane existing but empty /etc/nsswitch.conf on linux.

Signed-off-by: Natanael Copa <[email protected]>

Author: ncopa

src/net/conf_test.go

@@ -179,6 +179,15 @@ func TestConfHostLookupOrder(t *testing.T) {
 			},
 			hostTests: []nssHostTest{{"google.com", "myhostname", hostLookupFilesDNS}},
 		},
+		{
+			name: "linux_empty_nsswitch.conf",
+			c: &conf{
+				goos:   "linux",
+				nss:    nssStr(""),
+				resolv: defaultResolvConf,
+			},
+			hostTests: []nssHostTest{{"google.com", "myhostname", hostLookupFilesDNS}},
+		},
 		{
 			name: "files_mdns_dns",
 			c: &conf{