fix decoding race condition with new terminal sessions (#1366)

lib/components/term.js

@@ -150,6 +150,19 @@ export default class Term extends Component {
   }
 
   write(data) {
+    // sometimes the preference set above for
+    // `receive-encoding` is not known by the vt
+    // before we type to write (since the preference
+    // manager is asynchronous), so we force it to
+    // avoid buffering
+    // this fixes a race condition where sometimes
+    // opening new sessions results in broken
+    // output due to the term attempting to decode
+    // as `utf-8` instead of `raw`
+    if (this.term.vt.characterEncoding !== 'raw') {
+      this.term.vt.characterEncoding = 'raw';
+    }
+
     this.term.io.writeUTF8(data);
   }