imap is broken in CVS HEAD

[Thomas Glanzmann <sithglan@xxxxxxxxxxxxxxxxxxxx>]

Hello together,
IMAP is broken in current CVS HEAD. This is because the imap subfolder
isn't compiled with -D_FILE_OFFSET_BITS=64  while the rest is. So off_t
is once 32 bit in the CONTEXT struct and once 64 bit.

        Breakpoint 1, imap_read_headers (idata=0x812fe00, msgbegin=0, 
msgend=55) at message.c:199
        199       if (ctx->msgcount > oldmsgcount)
        (gdb) p & ctx->msgcount
        $2 = (int *) 0x81328dc
        (gdb) p ctx->msgcount
        $3 = 56
        (gdb) b mx_update_context
        Breakpoint 2, mx_update_context (ctx=0x81328a0, new_messages=56) at 
mx.c:1565
        1565      for (msgno = ctx->msgcount - new_messages; msgno < 
ctx->msgcount; msgno++)
        (gdb) p ctx->msgcount
        $5 = 0
        (gdb) p & ctx->msgcount
        $6 = (int *) 0x81328e4
        (gdb) p sizeof(CONTEXT)
        $7 = 108
        (gdb) frame 1
        #1  0x080bdc4f in imap_read_headers (idata=0x812fe00, msgbegin=0, 
msgend=55) at message.c:200
        200         mx_update_context (ctx, ctx->msgcount - oldmsgcount);
        (gdb) p sizeof(CONTEXT)
        $8 = 100

I don't know how to hack this into the automake/autoconf stuff, so no
patch is provided. However it would be nice if people could test there
stuff before putting them upstream. It just took me 3 hours to find that
bug. - Okay I should practice harder. Than I had tracked this down
within 10 minutes.

The symptoms are:

Fetching message headers... [50/56]Segmentation fault

        Thomas