mailkit-issue51.patch

diff --git a/MailKit/Net/Imap/ImapFolder.cs b/MailKit/Net/Imap/ImapFolder.cs
index 3de9c2f..9667d2f 100644
--- a/MailKit/Net/Imap/ImapFolder.cs
+++ b/MailKit/Net/Imap/ImapFolder.cs
@@ -2009,7 +2009,8 @@ namespace MailKit.Net.Imap {
 					if (token.Type != ImapTokenType.OpenParen)
 						throw ImapEngine.UnexpectedToken (token, false);
 
-					token = engine.ReadToken (ic.CancellationToken);
+					// Note: GMail's IMAP implementation is broken and does not quote strings with square brackets like it should
+					token = engine.Stream.ReadToken (ImapStream.AtomSpecialsAllowSquareBrackets, ic.CancellationToken);
 
 					summary.GMailLabels = new List<string> ();
 
@@ -2018,7 +2019,7 @@ namespace MailKit.Net.Imap {
 
 						summary.GMailLabels.Add (label);
 						
-						token = engine.ReadToken (ic.CancellationToken);
+						token = engine.Stream.ReadToken (ImapStream.AtomSpecialsAllowSquareBrackets, ic.CancellationToken);
 					}
 
 					if (token.Type != ImapTokenType.CloseParen)
diff --git a/MailKit/Net/Imap/ImapStream.cs b/MailKit/Net/Imap/ImapStream.cs
index e0df9dc..ccfba0d 100644
--- a/MailKit/Net/Imap/ImapStream.cs
+++ b/MailKit/Net/Imap/ImapStream.cs
@@ -57,7 +57,8 @@ namespace MailKit.Net.Imap {
 
 	class ImapStream : Stream
 	{
-		const string AtomSpecials = "()[]{%*\\\"\n";
+		public const string AtomSpecialsAllowSquareBrackets = "(){%*\\\"\n";
+		public const string AtomSpecials = "()[]{%*\\\"\n";
 		const int ReadAheadSize = 128;
 		const int BlockSize = 4096;
 		const int PadSize = 4;
@@ -354,9 +355,9 @@ namespace MailKit.Net.Imap {
 			return n;
 		}
 
-		static bool IsAtom (byte c)
+		static bool IsAtom (byte c, string specials)
 		{
-			return !IsCtrl (c) && !IsWhiteSpace (c) && AtomSpecials.IndexOf ((char) c) == -1;
+			return !IsCtrl (c) && !IsWhiteSpace (c) && specials.IndexOf ((char) c) == -1;
 		}
 
 		static bool IsCtrl (byte c)
@@ -421,7 +422,7 @@ namespace MailKit.Net.Imap {
 			}
 		}
 
-		unsafe string ReadAtomString (byte* inbuf, bool flag, CancellationToken cancellationToken)
+		unsafe string ReadAtomString (byte* inbuf, bool flag, string specials, CancellationToken cancellationToken)
 		{
 			var builder = new StringBuilder ();
 			byte* inptr = inbuf + inputIndex;
@@ -436,7 +437,7 @@ namespace MailKit.Net.Imap {
 					return "*";
 				}
 
-				while (IsAtom (*inptr))
+				while (IsAtom (*inptr, specials))
 					builder.Append ((char) *inptr++);
 
 				if (inptr < inend)
@@ -456,9 +457,9 @@ namespace MailKit.Net.Imap {
 			return builder.ToString ();
 		}
 
-		unsafe ImapToken ReadAtomToken (byte* inbuf, CancellationToken cancellationToken)
+		unsafe ImapToken ReadAtomToken (byte* inbuf, string specials, CancellationToken cancellationToken)
 		{
-			var atom = ReadAtomString (inbuf, false, cancellationToken);
+			var atom = ReadAtomString (inbuf, false, specials, cancellationToken);
 
 			return atom == "NIL" ? new ImapToken (ImapTokenType.Nil, atom) : new ImapToken (ImapTokenType.Atom, atom);
 		}
@@ -467,7 +468,7 @@ namespace MailKit.Net.Imap {
 		{
 			inputIndex++;
 
-			var flag = "\\" + ReadAtomString (inbuf, true, cancellationToken);
+			var flag = "\\" + ReadAtomString (inbuf, true, AtomSpecials, cancellationToken);
 
 			return new ImapToken (ImapTokenType.Flag, flag);
 		}
@@ -583,6 +584,11 @@ namespace MailKit.Net.Imap {
 		/// </exception>
 		public ImapToken ReadToken (CancellationToken cancellationToken)
 		{
+			return ReadToken (AtomSpecials, cancellationToken);
+		}
+
+		internal ImapToken ReadToken (string specials, CancellationToken cancellationToken)
+		{
 			CheckDisposed ();
 
 			if (nextToken != null) {
@@ -629,8 +635,8 @@ namespace MailKit.Net.Imap {
 					if (c == '\\')
 						return ReadFlagToken (inbuf, cancellationToken);
 
-					if (c != '+' && IsAtom (*inptr))
-						return ReadAtomToken (inbuf, cancellationToken);
+					if (c != '+' && IsAtom (*inptr, specials))
+						return ReadAtomToken (inbuf, specials, cancellationToken);
 
 					// special character token
 					inputIndex++;