[Dovecot] Problem in Search IMAP with spaces in Subject

[Giovanni Mancuso]

Hi,

I deliver a test email (with 4 spaces in subject) into a maildir:

Return-Path: <user at example.com>
Delivered-To: <user at example.com>
Received: from suse11 ([10.0.8.7])
        by suse11 (Dovecot) with LMTP id Pf6zDTCaiFOUXwAA4Q5jHg
        for <user at example.com>; Fri, 30 May 2014 16:48:16 +0200
From: <user at example.com>
To: <user at example.com>
Message-ID: <9704BC6A-28D9-CBF2-A1D6-DD54F6AA9D9D at newsvilpec.babel.it>
Subject: Test    4 Spaces

Test

But, if i search this email with 4 spaces in subject i don't find anthing:

telnet 0 143
Trying 0.0.0.0...
Connected to 0.
Escape character is '^]'.
* OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE
IDLE AUTH=PLAIN] Dovecot ready.
ab login user at example.com password
ab OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE
IDLE SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS
THREAD=ORDEREDSUBJECT MULTIAPPEND URL-PARTIAL CATENATE UNSELECT CHILDREN
NAMESPACE UIDPLUS LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH
ESORT SEARCHRES WITHIN CONTEXT=SEARCH LIST-STATUS SPECIAL-USE BINARY
MOVE QUOTA ACL RIGHTS=texk] Logged in
ab select inbox
* FLAGS (\Answered \Flagged \Deleted \Seen \Draft PEC_INBOX)
* OK [PERMANENTFLAGS (\Answered \Flagged \Deleted \Seen \Draft PEC_INBOX
\*)] Flags permitted.
* 1 EXISTS
* 1 RECENT
* OK [UNSEEN 1] First unseen.
* OK [UIDVALIDITY 1401785069] UIDs valid
* OK [UIDNEXT 2] Predicted next UID
ab OK [READ-WRITE] Select completed (0.002 secs).
a1 SEARCH CHARSET UTF-8 SUBJECT "Test    4 Spaces"
* SEARCH
a1 OK Search completed (0.001 secs).
a1 SEARCH CHARSET UTF-8 SUBJECT "Test 4 Spaces"
* SEARCH 1
a1 OK Search completed (0.000 secs).
ab logout
* BYE Logging out
ab OK Logout completed.
Connection closed by foreign host.

If i run the search with one space i find a mail.

I use dovecot v2.2.12 on Linux suse11 x86_64

Thanks