Parser: relax continuation response checking for broken IMAP server implementations

lib/Parser.js

@@ -10,14 +10,14 @@ var CH_LF = 10,
     LITPLACEHOLDER = String.fromCharCode(0),
     EMPTY_READCB = function(n) {},
     RE_INTEGER = /^\d+$/,
-    RE_PRECEDING = /^(?:\*|A\d+|\+) /,
+    RE_PRECEDING = /^(?:(?:\*|A\d+) )|\+ ?/,
     RE_BODYLITERAL = /BODY\[(.*)\] \{(\d+)\}$/i,
     RE_SEQNO = /^\* (\d+)/,
     RE_LISTCONTENT = /^\((.*)\)$/,
     RE_LITERAL = /\{(\d+)\}$/,
     RE_UNTAGGED = /^\* (?:(OK|NO|BAD|BYE|FLAGS|LIST|LSUB|SEARCH|STATUS|CAPABILITY|NAMESPACE|PREAUTH|SORT|THREAD|ESEARCH|QUOTA|QUOTAROOT)|(\d+) (EXPUNGE|FETCH|RECENT|EXISTS))(?: (?:\[([^\]]+)\] )?(.+))?$/i,
     RE_TAGGED = /^A(\d+) (OK|NO|BAD) (?:\[([^\]]+)\] )?(.+)$/i,
-    RE_CONTINUE = /^\+ (?:\[([^\]]+)\] )?(.+)$/i,
+    RE_CONTINUE = /^\+(?: (?:\[([^\]]+)\] )?(.+))?$/i,
     RE_CRLF = /\r\n/g,
     RE_HDR = /^([^:]+):[ \t]?(.+)?$/,
     RE_ENCWORD = /=\?([^?]*?)\?([qb])\?(.*?)\?=/gi,

test/test-parser.js

@@ -34,6 +34,13 @@ var CR = '\r', LF = '\n', CRLF = CR + LF;
               ],
     what: 'Continuation with text code'
   },
+  { source: ['+', CRLF],
+    expected: [ { textCode: undefined,
+                  text: undefined
+                }
+              ],
+    what: 'Continuation (broken -- RFC violation) sent by AOL IMAP'
+  },
   { source: ['* NAMESPACE ',
              '(("" "/")) ',
              '(("~" "/")) ',