[BUG] notmuch crashes on FreeBSD when synchronize_flags=true

[Tomi Ollila]

FYI (VirtualBox FreeBSD_10.1-64bit.7z from http://www.osboxes.org/freebsd/)
 
  root at osboxes:~/mail # rm -rf .notmuch/
  root at osboxes:~/mail # notmuch new
  Found 1 total files (that's not much mail).
  Warning: /root/mail/new/new.mail is an mbox containing a single message,
  likely caused by misconfigured mail delivery.  Support for single-message
  mboxes is deprecated and may be removed in the future.
  Abort (core dumped)

Built latest HEAD (bed8b6743) in $HOME/sw/notmuch

  root at osboxes:~/mail # rm -rf .notmuch/
  root at osboxes:~/mail # ~/sw/notmuch/notmuch new
  Found 2 total files (that's not much mail).
  Note: Ignoring non-mail file: /root/mail/notmuch.core
  Processed 2 total files in almost no time.
  Added 1 new message to the database.
  root at osboxes:~/mail #

OK, what worked :O (statically linked libnotmuch.4). Wat about shared...

  root at osboxes:~/mail # rm -rf .notmuch/ notmuch.core
  root at osboxes:~/mail # env LD_LIBRARY_PATH=$HOME/sw/notmuch/lib $HOME/sw/notmuch/notmuch-shared new
  Found 1 total files (that's not much mail).
  Abort (core dumped)

  root at osboxes:~/mail # gdb $HOME/sw/notmuch/notmuch-shared notmuch-shared.core
  GNU gdb 6.1.1 [FreeBSD]
  ...
  Core was generated by `notmuch-shared'.
  Program terminated with signal 6, Aborted.
  Reading symbols from /root/sw/notmuch/lib/libnotmuch.so.4...done.
  ...
  [New Thread 804406400 (LWP 100071/notmuch-shared)]
(gdb) bt
#0  0x00000008018d46ca in thr_kill () from /lib/libc.so.7
#1  0x00000008019a9149 in abort () from /lib/libc.so.7
#2  0x00000008022e242d in __cxa_rethrow () from /lib/libcxxrt.so.1
#3  0x0000000801c5d7d6 in Xapian::Document::Internal::remove_term ()
   from /usr/local/lib/libxapian.so.22
#4  0x00000008008500bc in _notmuch_message_remove_term
  (message=0x804468780, 
    prefix_name=0x800858414 "tag", value=<value optimized out>)
    at message.cc:1146
#5  0x000000080085158f in notmuch_message_remove_tag (message=0x804468780, 
    tag=0x800859167 "draft") at message.cc:1205
#6  0x0000000800851795 in notmuch_message_maildir_flags_to_tags (
    message=<value optimized out>) at message.cc:1312
#7  0x000000000040d9e5 in add_files (notmuch=0x8044542a0, 
    path=0x80445a3b0 "/root/mail/new", state=0x7fffffffe8b0)
    at notmuch-new.c:272
#8  0x000000000040d448 in add_files (notmuch=0x8044542a0, 
    path=0x804459fc0 "/root/mail", state=0x7fffffffe8b0) at
  notmuch-new.c:477
#9  0x000000000040c85f in notmuch_new_command (config=0x804468160, 
    argc=<value optimized out>, argv=<value optimized out>)
    at notmuch-new.c:1070
#10 0x0000000000408a23 in main (argc=<value optimized out>, 
    argv=0x7fffffffeb18) at notmuch.c:353

Due to just quick testing forgot my suggestion for CFLAGS... so...

   143 7:27 cd
   144 7:27 cd sw/notmuch
   145 7:27 make distclean
   146 7:28 gmake distclean
   147 7:28 env CFLAGS='-ggdb -O0' ./configure
   148 7:28 make
   149 7:28 gmake
   151 7:29 cd
   152 7:29 cd mail/
   153 7:29 ls
   154 7:29 rm notmuch-shared.core
   155 7:29 env LD_LIBRARY_PATH=$HOME/sw/notmuch/lib $HOME/sw/notmuch/notmuch-shared new
   156 7:29 gdb $HOME/sw/notmuch/notmuch-shared notmuch-shared.core

(gdb) bt
#0  0x00000008018f26ca in thr_kill () from /lib/libc.so.7
#1  0x00000008019c7149 in abort () from /lib/libc.so.7
#2  0x000000080230042d in __cxa_rethrow () from /lib/libcxxrt.so.1
#3  0x0000000801c7b7d6 in Xapian::Document::Internal::remove_term ()
   from /usr/local/lib/libxapian.so.22
#4  0x00000008008668b3 in _notmuch_message_remove_term
(message=0x804468780, 
    prefix_name=0x800874151 "tag", value=0x800874e97 "draft") at
    message.cc:1146
#5  0x0000000800868f76 in notmuch_message_remove_tag (message=0x804468780, 
    tag=0x800874e97 "draft") at message.cc:1205
#6  0x00000008008691d3 in notmuch_message_maildir_flags_to_tags (
    message=0x804468780) at message.cc:1312
#7  0x0000000000411295 in add_file (notmuch=0x8044542a0, 
    filename=0x80445c6e0 "/root/mail/new/new.mail", state=0x7fffffffe8b8)
    at notmuch-new.c:272
#8  0x00000000004102e2 in add_files (notmuch=0x8044542a0, 
    path=0x80445a3b0 "/root/mail/new", state=0x7fffffffe8b8)
    at notmuch-new.c:587
#9  0x000000000040fdad in add_files (notmuch=0x8044542a0, 
    path=0x804459fc0 "/root/mail", state=0x7fffffffe8b8) at
    notmuch-new.c:477
#10 0x000000000040ee81 in notmuch_new_command (config=0x804468160, argc=1, 
    argv=0x7fffffffeb20) at notmuch-new.c:1070
#11 0x0000000000409277 in main (argc=2, argv=0x7fffffffeb18) at
notmuch.c:353

Tomi