vi: changes to option handling

Since commit 70ee23399 (vi: code shrink) the ':set' command is
unable to process multiple options on a line.  Fix this by
temporarily null-terminating each option.

Change the default setting for all options to off to match vim.
Actually, 'flash' isn't an option in vim, only traditional vi,
where it's on by default.  In vim the corresponding option is
'visualbell' which defaults to off.  POSIX doesn't have either
of these.

Allow the abbreviation 'ts' for the 'tabstop' option.

Issue an error message if:

- an option is not implemented
- an option that takes a value has no '=' or has a 'no' prefix
- a boolean option has a '='

function                                             old     new   delta
colon                                               2944    3003     +59
.rodata                                           103171  103189     +18
vi_main                                              274     270      -4
setops                                                73       -     -73
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 2/1 up/down: 77/-77)              Total: 0 bytes

v2: Try harder to detect invalid options.  Thanks to Peter D for pointing
    this out.

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

0 files changed, 0 insertions, 0 deletions