When playing with large numbers of IMAP keywords on dovecot-1.2.6 imap
crashed:

Panic: pool_data_stack_realloc(): stack frame changed

Looks like either maildir_file_do() shouldn't T_BEGIN/T_END or the
keywords array should start larger.

0 libSystem.B.dylib 0x00007fff875f4eba __kill + 10 1 libSystem.B.dylib 0x00007fff875f4eac kill + 14 2 libSystem.B.dylib 0x00007fff87683519 raise + 25 3 libSystem.B.dylib 0x00007fff876a4e12 abort + 90 4 imap 0x000000010008022f
default_fatal_finish + 69 5 imap 0x000000010007f4b4
i_internal_error_handler + 0 6 imap 0x000000010007fa36 i_info + 0 7 imap 0x000000010008987e
pool_data_stack_realloc + 150 8 imap 0x000000010007d77c buffer_alloc + 60 9 imap 0x000000010007d947
buffer_check_limits + 113 10 imap 0x000000010007dde8 buffer_append + 38 11 imap 0x0000000100060c50
mail_index_sync_keywords_apply + 88 12 imap 0x0000000100043f20
index_sync_changes_apply + 184 13 imap 0x0000000100026b6d
maildir_sync_flags + 131 14 imap 0x000000010002a7c6
maildir_file_do_try + 334 15 imap 0x000000010002a34e maildir_file_do

• 58 16 imap 0x00000001000263c4
  maildir_sync_index + 1102 17 imap 0x000000010002588e
  maildir_sync_context + 806 18 imap 0x0000000100025aa4
  maildir_storage_sync_init + 92 19 imap 0x000000010004ad9c
  mailbox_sync_init + 16 20 imap 0x000000010000ebc8 imap_sync_init +
  98 21 imap 0x000000010000fd29 cmd_sync_delayed
• 425 22 imap 0x000000010000814c
  client_handle_input + 442 23 imap 0x00000001000074ea client_input + 104 24 imap 0x0000000100087c20
  io_loop_handler_run + 246 25 imap 0x0000000100086f16 io_loop_run + 56 26 imap 0x000000010001063b main + 1629 27 imap 0x00000001000010b8 start + 52

also

0 libSystem.B.dylib 0x00007fff875f4eba __kill + 10 1 libSystem.B.dylib 0x00007fff875f4eac kill + 14 2 libSystem.B.dylib 0x00007fff87683519 raise + 25 3 libSystem.B.dylib 0x00007fff876a4e12 abort + 90 4 imap 0x000000010008022f
default_fatal_finish + 69 5 imap 0x000000010007f4b4
i_internal_error_handler + 0 6 imap 0x000000010007fa36 i_info + 0 7 imap 0x000000010008987e
pool_data_stack_realloc + 150 8 imap 0x000000010007d77c buffer_alloc + 60 9 imap 0x000000010007d947
buffer_check_limits + 113 10 imap 0x000000010007dde8 buffer_append + 38 11 imap 0x0000000100060c50
mail_index_sync_keywords_apply + 88 12 imap 0x0000000100043f20
index_sync_changes_apply + 184 13 imap 0x0000000100026b6d
maildir_sync_flags + 131 14 imap 0x000000010002a7c6
maildir_file_do_try + 334 15 imap 0x000000010002a34e maildir_file_do

• 58 16 imap 0x00000001000263c4
  maildir_sync_index + 1102 17 imap 0x000000010002588e
  maildir_sync_context + 806 18 imap 0x0000000100025aa4
  maildir_storage_sync_init + 92 19 imap 0x000000010004ad9c
  mailbox_sync_init + 16 20 imap 0x000000010004ade0 mailbox_sync + 48 21 imap 0x00000001000058b8 cmd_select_full
• 1748 22 imap 0x0000000100005d9b cmd_select + 11 23 imap 0x0000000100007de6
  client_command_input + 36 24 imap 0x0000000100007f17
  client_command_input + 341 25 imap 0x0000000100008086
  client_handle_input + 244 26 imap 0x00000001000074ea client_input + 104 27 imap 0x0000000100087c20
  io_loop_handler_run + 246 28 imap 0x0000000100086f16 io_loop_run + 56 29 imap 0x000000010001063b main + 1629 30 imap 0x00000001000010b8 start + 52