of storing a full grid_cell with UTF-8 data and everything, store a new
type grid_cell_entry. This can either be the cell itself (for ASCII
cells), or an offset into an extended array (per line) for UTF-8
data.
This avoid a large (8 byte) overhead on non-UTF-8 cells (by far the
majority for most users) without the complexity of the shadow array we
had before. Grid memory without any UTF-8 is about half.
The disadvantage that cells can no longer be modified in place and need
to be copied out of the grid and back but it turned out to be lot less
complicated than I expected.
uint64_t and converting UTF-8 to Unicode on input and the reverse on
output. (This allows key bindings, there are still omissions - the
largest being that the various prompts do not accept UTF-8.)
around, we can't use file descriptors for the working directory because
we will be unable to pass it to a privileged process to tell it where to
read or write files or spawn children. So move tmux back to using
strings for the current working directory. We try to check it exists
with access() when it is set but ultimately fall back to ~ if it fails
at time of use (or / if that fails too).
#{=10:...} length limit, add #{t:...} to convert a time_t format to a
string, #{b:...} for basename and #{d:...} for dirname. Remove all the
foo_string time formats as they can now be replaced by "t:", for example
#{window_activity_string} becomes #{t:window_activity}.
the main loop after events that may have changed the pane, but do so at
most once every 500 millis. If the pane changed too soon, use a timer to
ensure that a check happens later.
can't do the name check every loop, because that is too expensive, and
we can't make sure it only happens infrequently because we have no idea
when the next change will happen.
but that can only happen when we have already been woken up by a read
event, so there is no need for a timer, we can just check the changed
flag on the end of that read event (we already loop over the windows to
check for bells etc anyway).
