fix(terminal): fix resize crash with pending scrollback (#14891)

refresh_scrollback assumes pending scrollback rows exist only if the
terminal window height decreased (or the screen was full).

However, after accumulating scrollback, it's possible in some cases for
the terminal height to increase before refresh_scrollback is called via
invalidation (especially when the terminal buffer isn't initially
displayed in a window before nvim_open_term), which may crash.

As we'll have enough room for some scrollback rows, just append them to
the top of the buffer until it fills the window, then continue with the
previous logic for any remaining scrollback rows if necessary.

0 files changed, 0 insertions, 0 deletions