Parser: check regexp success before trying to use captures

lib/Parser.js

@@ -161,27 +161,23 @@ Parser.prototype._parse = function(data) {
 };
 
 Parser.prototype._resTagged = function() {
+  var m;
   if (m = RE_LITERAL.exec(this._buffer)) {
     // non-BODY literal -- buffer it
     this._buffer = this._buffer.replace(RE_LITERAL, LITPLACEHOLDER);
     this._literallen = parseInt(m[1], 10);
-  } else {
+  } else if (m = RE_TAGGED.exec(this._buffer)) {
-    var m = RE_TAGGED.exec(this._buffer),
-        tagnum = parseInt(m[1], 10),
-        type = m[2].toLowerCase(),
-        textCode = (m[3] ? parseTextCode(m[3], this._literals) : m[3]),
-        text = m[4];
     this._buffer = '';
-
     this._literals = [];
 
     this.emit('tagged', {
-      type: type,
+      type: m[2].toLowerCase(),
-      tagnum: tagnum,
+      tagnum: parseInt(m[1], 10),
-      textCode: textCode,
+      textCode: (m[3] ? parseTextCode(m[3], this._literals) : m[3]),
-      text: text
+      text: m[4]
     });
-  }
+  } else
+    this._buffer = '';
 };
 
 Parser.prototype._resUntagged = function() {
@@ -282,9 +278,15 @@ Parser.prototype._resUntagged = function() {
 Parser.prototype._resContinue = function() {
   var m = RE_CONTINUE.exec(this._buffer),
       textCode,
-      text = m[2];
+      text;
+
   this._buffer = '';
 
+  if (!m)
+    return;
+
+  text = m[2];
+
   if (m[1] !== undefined)
     textCode = parseTextCode(m[1], this._literals);