fix: Only report http2 support if the http2 feature is enabled

Fixes rustls#143

Author: Markus Westerlind

Cargo.toml

@@ -28,6 +28,7 @@ futures-util = { version = "0.3.1", default-features = false }
 
 [features]
 default = ["native-tokio"]
+http2 = ["hyper/http2"]
 webpki-tokio = ["tokio-runtime", "webpki-roots"]
 native-tokio = ["tokio-runtime", "rustls-native-certs"]
 tokio-runtime =  ["hyper/runtime", "ct-logs"]

src/connector.rs

@@ -61,7 +61,15 @@ impl HttpsConnector<HttpConnector> {
         let mut http = HttpConnector::new();
         http.enforce_http(false);
 
-        config.alpn_protocols = vec![b"h2".to_vec(), b"http/1.1".to_vec()];
+        #[cfg(feature = "http2")]
+        {
+            config.alpn_protocols = vec![b"h2".to_vec(), b"http/1.1".to_vec()];
+        }
+        #[cfg(not(feature = "http2"))]
+        {
+            config.alpn_protocols = vec![b"http/1.1".to_vec()];
+        }
+
         config.ct_logs = Some(&ct_logs::LOGS);
         (http, config).into()
     }