provide for better compatibility with attach.js

demo/main.js

@@ -112,7 +112,9 @@ function createTerminal() {
         socket.onclose = runFakeTerminal;
         socket.onerror = runFakeTerminal;
 
-        term.zmodemAttach(socket);
+        term.zmodemAttach(socket, {
+            noTerminalWriteOutsideSession: true,
+        } );
 
         term.on("zmodemDetect", (detection) => {
             term.detach();

src/addons/attach/attach.js

@@ -56,11 +56,27 @@
       }
     };
 
+    var myTextDecoder;
+
     term._getMessage = function (ev) {
+      var str;
+      if (typeof ev.data === "object") {
+        if (ev.data instanceof ArrayBuffer) {
+            if (!myTextDecoder) {
+              myTextDecoder = new TextDecoder();
+            }
+
+            str = myTextDecoder.decode( ev.data );
+        }
+        else {
+          throw "TODO: handle Blob?";
+        }
+      }
+
       if (buffered) {
-        term._pushToBuffer(ev.data);
+        term._pushToBuffer(str || ev.data);
       } else {
-        term.write(ev.data);
+        term.write(str || ev.data);
       }
     };
 

src/addons/zmodem/zmodem.js

@@ -41,18 +41,28 @@
     Object.assign(
         Terminal.prototype,
         {
-            zmodemAttach: function zmodemAttach(ws) {
+            zmodemAttach: function zmodemAttach(ws, opts) {
                 var term = this;
 
+                if (!opts) opts = {};
+
                 var senderFunc = function _ws_sender_func(octets) {
                     ws.send( new Uint8Array(octets) );
                 };
 
-                var zsentry = new Zmodem.Sentry( {
+                var zsentry;
+
+                function _shouldWrite() {
+                    return !!zsentry.get_confirmed_session() || !opts.noTerminalWriteOutsideSession;
+                }
+
+                zsentry = new Zmodem.Sentry( {
                     to_terminal: function _to_terminal(octets) {
-                        term.write(
-                            String.fromCharCode.apply(String, octets)
-                        );
+                        if (_shouldWrite()) {
+                            term.write(
+                                String.fromCharCode.apply(String, octets)
+                            );
+                        }
                     },
 
                     sender: senderFunc,
@@ -68,9 +78,14 @@
 
                 function handleWSMessage(evt) {
 
-                    //For some reason the first message from the server is text.
+                    //In testing with xterm.js’s demo the first message was
+                    //always text even if the rest were binary. While that
+                    //may be specific to xterm.js’s demo, ultimately we
+                    //should reject anything that isn’t binary.
                     if (typeof evt.data === "string") {
-                        term.write(evt.data);
+                        if (_shouldWrite()) {
+                            term.write(evt.data);
+                        }
                     }
                     else {
                         zsentry.consume(evt.data);