vi: don't overwrite existing file

If the name of the file being written doesn't match the current
filename and the output file already exists vi should issue a
warning and not overwrite the file.

Because the test only compares the file names it's somewhat over-
protective.  If the current file name is 'my_text' and the user tries
to save to './my_text' they'll be prevented from doing so.

function                                             old     new   delta
colon                                               3092    3151     +59
.rodata                                           105118  105146     +28
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 87/0)               Total: 87 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
1 file changed