Fix artifact directories not having traversal permissions (#4075)

It turns out that Windows requires the executable bit set if the
`BYPASS_TRAVERSE_CHECKING` privilege is not attached to a user's
account.  It's simply more correct to ensure that our directories have
this bit set, and unfortunately our `filemode()` function call is
not complete on Windows and does not include this bit, so we manually
add it in on Windows.

Author: staticfloat

src/Artifacts.jl

@@ -84,7 +84,14 @@ function _mv_temp_artifact_dir(temp_dir::String, new_path::String)::Nothing
         err = ccall(:jl_fs_rename, Int32, (Cstring, Cstring), temp_dir, new_path)
         if err ≥ 0
             # rename worked
-            chmod(new_path, filemode(dirname(new_path)))
+            new_path_mode = filemode(dirname(new_path))
+            if Sys.iswindows()
+                # If this is Windows, ensure the directory mode is executable,
+                # as `filemode()` is incomplete.  Some day, that may not be the
+                # case, there exists a test that will fail if this is changes.
+                new_path_mode |= 0o111
+            end
+            chmod(new_path, new_path_mode)
             set_readonly(new_path)
             return
         else

test/artifacts.jl

@@ -823,4 +823,16 @@ end
     end
 end
 
+if Sys.iswindows()
+    @testset "filemode(dir) non-executable on windows" begin
+        mktempdir() do dir
+            touch(joinpath(dir, "foo"))
+            @test !isempty(readdir(dir))
+            # This technically should be true, the fact that it's not is
+            # a wrinkle of libuv, it would be nice to fix it and so if we
+            # do, this test will let us know.
+            @test filemode(dir) & 0o001 == 0
+        end
+    end
+end
 end # module