Test for BufWritePre autocommand that deletes or unloads the buffer.

STARTTEST
:so small.vim
:au BufWritePre Xxx1 bunload
:au BufWritePre Xxx2 bwipe
/^start of
A1:.,/end of/w! Xxx1  " write test file Xxx1
$r2:.,/end of/w! Xxx2   " write test file Xxx2
:e! Xxx2                " edit Xxx2
:bdel test8.in		" delete this file from the buffer list
:e Xxx1                 " edit Xxx1
:w                      " write it, will unload it and give an error msg
:w! test.out            " Write contents of this file
:e! Xxx2                " start editing Xxx2
:bwipe test.out         " remove test.out from the buffer list
:w                      " write it, will delete the buffer and give an error msg
:w >>test.out           " Append contents of this file
:qa!
ENDTEST

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	test
end of Xxx