[Dovecot] FTS and compound searches

[Tony Pyro]

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!