improve trusted location detection

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)

registry/registry.go

@@ -766,7 +766,7 @@ func trustedLocation(req *http.Request) bool {
 	}
 
 	for _, trusted := range trusteds {
-		if strings.HasSuffix(hostname, trusted) {
+		if hostname == trusted || strings.HasSuffix(hostname, "."+trusted) {
 			return true
 		}
 	}

registry/registry_test.go

@@ -235,7 +235,7 @@ func TestValidRepositoryName(t *testing.T) {
 }
 
 func TestTrustedLocation(t *testing.T) {
-	for _, url := range []string{"http://example.com", "https://example.com:7777", "http://docker.io", "http://test.docker.io"} {
+	for _, url := range []string{"http://example.com", "https://example.com:7777", "http://docker.io", "http://test.docker.io", "https://fakedocker.com"} {
 		req, _ := http.NewRequest("GET", url, nil)
 		if trustedLocation(req) == true {
 			t.Fatalf("'%s' shouldn't be detected as a trusted location", url)