[Dovecot] FTS and compound searches

Hello,

New subscriber here. I noticed that the FTS index is not used in compound searches. Is this expected? Tested in 2.0.0 and 2.0.8:

. search BODY "waldo"

• SEARCH . OK Search completed (0.000 secs). . SEARCH CHARSET UTF-8 OR SUBJECT "waldo" FROM "waldo"
• SEARCH . OK Search completed (1.768 secs). . SEARCH CHARSET UTF-8 OR SUBJECT "waldo" BODY "waldo"
• OK Searched 0% of the mailbox, ETA 9605:25
• OK Searched 4% of the mailbox, ETA 6:39
• OK Searched 6% of the mailbox, ETA 6:58
• OK Searched 8% of the mailbox, ETA 6:54

It's a problem for us because the Afterlogic webmail client does not offer a body-only search. The two search options are From + To + Subject, or "entire messages", which puts together a large OR query:

SRCH1069 SEARCH CHARSET UTF-8 OR (OR (OR FROM "waldo" TO "waldo") SUBJECT "waldo") BODY "waldo"

I also checked to see whether the header fields are included in the FTS index but it didn't appear so. I got more results from the search "TO gmail.com" than from "BODY gmail.com"

plugin { fts = squat } protocol imap { mail_plugins = " fts fts_squat" }

Thanks!