vi: deal with invalid movements in shift commands

Since commit 25d259264 (vi: make buffer handling more vi-like)
find_range() can return early when an invalid movement is
specified.

The call to find_range() in the code that handles shift commands
('<' and '>') doesn't check for this condition.  Previously this
only resulted in the current line being shifted but it can now
result in a segfault.

Check for an invalid movement and notify the user without taking
any further action.

function                                             old     new   delta
do_cmd                                              4890    4898      +8
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(add/remove: 0/0 grow/shrink: 1/0 up/down: 8/0)                 Total: 8 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