Make sure REPL doesn't get borked when invalid REPL keywords are entered

lib/repl.js

@@ -84,6 +84,7 @@ function REPLServer(prompt, stream) {
   });
 
   rli.addListener('line', function(cmd) {
+    var skipCatchall = false;
     cmd = trimWhitespace(cmd);
 
     // Check to see if a REPL keyword was used. If it returns true,
@@ -92,9 +93,15 @@ function REPLServer(prompt, stream) {
       var matches = cmd.match(/^(\.[^\s]+)\s*(.*)$/);
       var keyword = matches && matches[1];
       var rest = matches && matches[2];
-      if (self.parseREPLKeyword(keyword, rest) === true) return;
+      if (self.parseREPLKeyword(keyword, rest) === true) {
+        return;
+      } else {
+        self.stream.write('Invalid REPL keyword\n');
+        skipCatchall = true;
+      }
     }
 
+    if (!skipCatchall) {
       // The catchall for errors
       try {
         self.buffered_cmd += cmd;
@@ -130,6 +137,7 @@ function REPLServer(prompt, stream) {
         }
         self.buffered_cmd = '';
       }
+    }
 
     self.displayPrompt();
   });