Close #2270

https://docs.travis-ci.com/user/installing-dependencies/#installing-packages-on-macos

> By default, the Homebrew addon will not run brew update before
> installing packages. brew update can take a long time and slow down your
> builds.

Some programs use it to set the background color for the whole line.

  fzf --preview "printf 'normal \x1b[42mgreen\x1b[0K \x1b[43myellow\x1b[m\nnormal again'"

  fzf --preview 'delta <(echo foo) <(echo bar) < /dev/tty'

Fix #2249

Fix #2254

- Properly handle extra chars in the buffer. Patch suggested by @mckelly2833.
- Support alt-arrow sequences in \e[1;3A format
- Support shift-alt-arrow sequences in \e[1;10A format

Fix #2258

/cc @Caid11

The clean-up is done in s:collect(), so let's make sure it's run before
we may terminate due to CTRL-C or ESC (or some other error code) in
s:exit_handler().

Fix https://github.com/junegunn/fzf.vim/issues/1176

I forgot to add the "not _fzf" check into __fzf_orig_completion, so
invoking it twice would rewrite the _fzf_orig_completion_xxx variables
and then cause an endless loop when completion is requested.

Fixes: ef2c29d5 ("[bash-completion] Optimize __fzf_orig_completion_filter")

Commit d4ad4a25 slowed loading of completion.bash significantly (on my
laptop from 10 ms to 30 ms), then 54891d11 improved that (to 20 ms) but
it still stands out as the heavy part of my .bashrc.

Rewriting __fzf_orig_completion_filter to pure bash without forking to
sed/awk brings this back under 10 ms.

before:

    $ HISTFILE=/tmp/bashhist hyperfine 'bash --rcfile shell/completion.bash -i'
    Benchmark #1: bash --rcfile shell/completion.bash -i
      Time (mean ± σ):      21.2 ms ±   0.3 ms    [User: 24.9 ms, System: 6.4 ms]
      Range (min … max):    20.7 ms …  23.3 ms    132 runs

after:

    $ HISTFILE=/tmp/bashhist hyperfine 'bash --rcfile shell/completion.bash -i'
    Benchmark #1: bash --rcfile shell/completion.bash -i
      Time (mean ± σ):       9.6 ms ±   0.3 ms    [User: 8.0 ms, System: 2.2 ms]
      Range (min … max):     9.3 ms …  11.4 ms    298 runs

Fixes: d4ad4a25 ("[bash-completion] Fix default alias/variable completion")
Fixes: 54891d11 ("[bash-completion] Minor optimization")

This prevents mistakes like the one fixed by the previous commit, and
also speeds bash startup a tiny bit:

before:

    $ HISTFILE=/tmp/bashhist hyperfine 'bash --rcfile shell/completion.bash -i'
    Benchmark #1: bash --rcfile shell/completion.bash -i
      Time (mean ± σ):      22.4 ms ±   0.6 ms    [User: 28.7 ms, System: 7.8 ms]
      Range (min … max):    21.7 ms …  25.2 ms    123 runs

after:

    $ HISTFILE=/tmp/bashhist hyperfine 'bash --rcfile shell/completion.bash -i'
    Benchmark #1: bash --rcfile shell/completion.bash -i
      Time (mean ± σ):      21.2 ms ±   0.3 ms    [User: 24.9 ms, System: 6.4 ms]
      Range (min … max):    20.7 ms …  23.3 ms    132 runs

This doesn't look right:

    $ complete | grep ' _.$'
    complete _a
    complete _v

The __fzf_orig_completion_filter invocation in _fzf_setup_completion
needs the /-F/ filter, just like all the other invocations.

Fixes: d4ad4a25 ("[bash-completion] Fix default alias/variable completion")

Close #2241

Fix https://github.com/junegunn/fzf.vim/issues/1141

Fix #2231

Fix #2239

For me, this fixes invalid popup size problem on Windows GVim

This reverts commit 7915e365
due to https://github.com/junegunn/fzf.vim/issues/1152#issuecomment-719696495.

Fix #1766

The output may contain some unexpected warning messages from the shell
if it's not properly configured. While such extra messages should be
properly addressed by the user, we can ignore them by checking the
last line of the output instead of the first line.

Related: https://github.com/junegunn/fzf.vim/commit/bd3a021ec11617c56e6aa95578fee619445b029d

So that you can still build and use fzf even when the precise version
number is not injected via -ldflags.

Fix #2229