patch 7.4.730 Problem: When setting the crypt key and using a swap file, text may be encrypted twice or unencrypted text remains in the swap file. (Issue 369) Solution: Call ml_preserve() before re-encrypting. Set correct index for next pointer block.

" Settings for test script execution
" Always use "COMMAND.COM", don't use the value of "$SHELL".
set shell=c:\COMMAND.COM shellquote= shellxquote= shellcmdflag=/c shellredir=>
" This is used only when the +eval feature is available.
if executable("cmd.exe")
   set shell=cmd.exe
endif