Avoid clearing the screen in most situations. NOT_VALID should be
equivalent to CLEAR unless some external force messed up the terminal,
for these situations <c-l> and :mode will still clear the screen.
Also eliminate some obsolete code in screen.c, that dealt with that in
vim drawing window 1 can mess up window 2, but this never happens in
nvim.
But what about slow terminals? There is two common meanings in which
a terminal is said to be "slow":
Most commonly (and in the sense of vim:s nottyfast) it means low
bandwidth for sending bytes from nvim to the terminal. If the screen is
very similar before and after the update_screen(CLEAR) this change
should reduce bandwidth. If the screen is quite different, but there is
no new regions of contiguous whitespace, clearing doesn't reduce
bandwidth significantly. If the new screen contains a lot of whitespace,
it will depend of if vsplits are used or not: as long as there is no
vsplits, ce is used to cheaply clear the rest of the line, so
full-screen clear is not needed to reduce bandwith. However a left
vsplit currently needs to be padded with whitespace all the way to the
separator. It is possible ec (clear N chars) can be used to reduce
bandwidth here if this is a problem. (All of this assumes that one
doesn't set Normal guibg=... on a non-BCE terminal, if you do you are
doomed regardless of this change).
Slow can also mean that drawing pixels on the screen is slow. E-ink
screens is a recent example. Avoiding clearing and redrawing the
unchanged part of the screen will always improve performance in these
cases.
clang scan-build noticed that find_command() may bitmask `eap->flags`.
cmd_can_preview() only uses `ea.cmdidx`, but let's fix the warning...
Found by clang scan-build 5.0
Problem: Using try/catch in timer does not prevent it from being stopped.
Solution: Reset the exception context and use did_emsg instead of
called_emsg.
e723c42836
Problem: Can't use input() in a timer callback. (Cosmin Popescu)
Solution: Reset vgetc_busy and set timer_busy. (Ozaki Kiichi, closesvim/vim#1790,
closesvim/vim#1129)
1e8e14552e
Problem: Cursorline not removed when using 'cursorbind'. (Justin Keyes)
Solution: Store the last cursor line per window. (closesvim/vim#3488)
4a5abbd613
Problem: User doesn't notice file does not exist when swap file does.
Solution: Add a note that the file cannot be found. Make the "still
running" notice stand out.
d6105cb408
Problem: When making backups is disabled and conversion with iconv fails
the written file is truncated. (Luo Chen)
Solution: First try converting the file and write the file only when it did
not fail. (partly by Christian Brabandt)
e6bf655bc4
Problem: There is no easy way to get the global directory, esp. if some
windows have a local directory.
Solution: Make getcwd(-1) return the global directory. (Andy Massimino,
closesvim/vim#2606)
5459129af2
Problem: One character cmdline abbreviation not triggered after '<,'>.
Solution: Skip over the special range. (Christian Brabandt, closesvim/vim#2320)
5e3423d192
Problem: MS-Windows: Filter command with pipe character fails. (Johannes
Riecken)
Solution: Find the pipe character outside of quotes. (Yasuhiro Matsumoto,
closesvim/vim#1743, closesvim/vim#3523)
0664089ecc
Problem: Deleting in a block selection causes problems.
Solution: Check the length of the line before adding bd.textcol and
bd.textlen. (Christian Brabandt, closesvim/vim#2825)
35e802e713
Windows has "Read and execute" permission via ACL
but nvim and libuv do not support ACL.
Windows does not support the executable bit in chmod-style permissions
but it is safe to assume that if the file exists and is readable,
then it is most likely executable.
This means that win.ini and shell32.dll are "executable"
because they exist, are readable, and are in PATH.
PATHEXT does not affect the executable permission of a file;
it exists to run files on the shell while omitting the file extension.
Assume that PATHEXT is intended for cmd.exe only
because powershell can execute powershell files (ie. *.ps1)
without changing PATHEXT or related cmd.exe environment variable.
In the future, nvim should check the outputs of 'assoc' and 'ftype',
cmd.exe internal commands, or check the registry.
Powershell can be used for ACL if C++/C# API is too difficult to use.
