Wrong handling of EOF lines

[wookayin]

Upon Isort-ing the following buffer, a new line will be added near the EOF.

Before:

1 import os
2 import sys
3
4 def foo(a):
5     pass

After (see Line 7, a new blank line is added):

1 import os
2 import sys
3
4
5 def foo(a):
6     pass
7

Running isort from command-line doesn't have such issues: it correctly organizes import statements, but does not add any blank lines at the end of the file. I think updating the neovim buffer contents with isort output did not handle EOF properly.

I was using neovim 0.5.1 and isort 4.3.21.