fix header value parsing behavior for folded lines

lib/imap.parsers.js

@@ -1,8 +1,7 @@
 var utils = require('./imap.utilities');
 
 var reCRLF = /\r\n/g,
-    reHdr = /^([^:]+):\s?(.+)?$/,
-    reHdrFold = /^\s+(.+)$/;
+    reHdr = /^([^:]+):[ \t]?(.+)?$/;
 
 exports.convStr = function(str, literals) {
   if (str[0] === '"')
@@ -29,8 +28,9 @@ exports.parseHeaders = function(str) {
       continue;
     if (lines[i][0] === '\t' || lines[i][0] === ' ') {
       // folded header content
-      m = reHdrFold.exec(lines[i]);
-      headers[h][headers[h].length - 1] += m[1];
+      // RFC2822 says to just remove the CRLF and not the whitespace following
+      // it, so we follow the RFC and include the leading whitespace ...
+      headers[h][headers[h].length - 1] += lines[i];
     } else {
       m = reHdr.exec(lines[i]);
       h = m[1].toLowerCase();