vi: reject change command when motion fails

If the motion command used to define the range of a change, yank or
delete fails the whole command should be rejected.  BusyBox vi already
handled failed searches in these circumstances.  Add some more cases:

- non-existent mark: d'x

- movement beyond end of file: c99999+ or 99999<<

This is implemented using a global variable which is set when a command
error is detected.  Unlike the case of motion within a line it's
insufficient to check that the motion command doesn't move the cursor:
this fails to process 'LyL' correctly, for example, as the second 'L'
doesn't move the cursor.

function                                             old     new   delta
indicate_error                                        75      82      +7
find_range                                           686     692      +6
do_cmd                                              4851    4852      +1
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/0 up/down: 14/0)               Total: 14 bytes

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

0 files changed, 0 insertions, 0 deletions