and use tty_clear_line (which will choose the best escape sequence) to
clear any batches of cells with that flag when redrawing a line from the
stored screen.
loop, and fix a check to avoid a potential out-of-bounds access. Problem
reported by Yuxiang Qin and tracked down by Karl Beldan; GitHub issue
1352.
Also a man page fix request by jmc@.
performance cost with a large history. Instead change back to using a
second grid and copying modified lines over which is much faster (this
doesn't revert to the old code however which didn't support UTF-8
properly). GitHub issue 1249.
cell was overwritten. With a large history this can be a substantial
amount of memory. To reduce this, compact each extended cell list to
only cells in use as it is scrolled off the visible screen into the
history. From Dan Aloni in GitHub issue 1062.
background is default (8), introduce an explicit free function and use
it where a free alone is needed. Likewise, use memmove directly rather
than grid_move_lines where it makes sense. Based on a memory leak fix by
Dan Aloni in GitHub issue 1051.
together instead of handling them one by one. This is significantly
faster. Sequences are terminated when we reach the end of the line, fill
the internal buffer, or a different character is seen by the input
parser (an escape sequence, or UTF-8).
Rather than writing collected sequences out immediately, hold them until
it is necessary (another screen modification, or we consume all
available data). This means we can discard changes that would have no
effect (for example, lines that would just be scrolled off the screen or
cleared). This reduces the total amount of data we write out to the
terminal - not important for fast terminals, but a big help with slow
(like xterm).
sequences (notable EL and ED but also IL, DL, ICH, DCH) create blank
cells using the current background colour rather than the default
colour.
On modern systems BCE doesn't really have many benefits, but most other
terminals now support it, some (lazy) applications rely on it, and it is
not hard to include now that we have pane background colours anyway.
Mostly written by Sean Haugh.
instead track them as change (dirty) and update them once at the end,
saves much time if repeatedly writing the same cell. Also fix comparison
of cells being equal in a few places (memcmp is not enough).
