fix(tui): do not remove SIGWINCH handler when resize events are enabled (#35221)

When Nvim is started in one terminal emulator,
suspended, and later resumed in a different terminal emulator (as can
happen when using e.g. a multiplexer), the new terminal emulator will
not have all of the same modes enabled that the original terminal
emulator had. This is a problem in particular for in-band resize events
because we were disabling the SIGWINCH signal handler when we determined
that the terminal supported this mode.

However, if the new terminal does not support this mode then the
SIGWINCH handler remains disabled, and Neovim no longer properly
resizes. Instead of disabling the SIGWINCH handler, we track the state
of the resize events mode internally. If the mode is enabled then we
return early from the SIGWINCH handler before performing any ioctls or
other system calls. But if the mode is not enabled we proceed as normal.

0 files changed, 0 insertions, 0 deletions