split: clamp minimum split size to 1

The split command allows delta size changes, which triggers a condition
where the split can overflow into the dirlist. Clamp the minimum size of
a split or vsplit to "1" to prevent the view from overflowing, or
completely covering the message list. A split of 0 will still clear the
split.

Reported-by: Koni Marti <koni.marti@gmail.com>
Signed-off-by: Tim Culverhouse <tim@timculverhouse.com>
Acked-by: Robin Jarry <robin@jarry.cc>

0 files changed, 0 insertions, 0 deletions