Check again if the tty is open inside the IO lock (#51222)

This can cause segfaults when exiting julia.

Co-authored-by: Valentin Churavy <[email protected]>
(cherry picked from commit b3741c0)

Author: 2 people

base/stream.jl

@@ -565,7 +565,6 @@ displaysize() = (parse(Int, get(ENV, "LINES",   "24")),
                  parse(Int, get(ENV, "COLUMNS", "80")))::Tuple{Int, Int}
 
 function displaysize(io::TTY)
-    # A workaround for #34620 and #26687 (this still has the TOCTOU problem).
     check_open(io)
 
     local h::Int, w::Int
@@ -588,6 +587,7 @@ function displaysize(io::TTY)
     s1 = Ref{Int32}(0)
     s2 = Ref{Int32}(0)
     iolock_begin()
+    check_open(io)
     Base.uv_error("size (TTY)", ccall(:uv_tty_get_winsize,
                                       Int32, (Ptr{Cvoid}, Ptr{Int32}, Ptr{Int32}),
                                       io, s1, s2) != 0)