isort==5 regression: force_single_line removes preceding comment lines

[nchepanov]

Given

an example.py:

# A comment
# A comment

# Oh no, I'm gone :'(
from moo import foo

Observed

➜ isort --diff --check --force-single-line-imports example.py
ERROR: example.py Imports are incorrectly sorted and/or formatted.
--- example.py:before	2020-07-07 10:51:36.483557
+++ example.py:after	2020-07-07 10:51:44.531403
@@ -1,5 +1,4 @@
 # A comment
 # A comment

-# Oh no, I'm gone :'(
 from moo import foo

Expected

The comment is not deleted, as it was with isort==4.3.21

➜ pip freeze
isort==4.3.21
➜ isort --diff --check --force-single-line-imports example.py
(success)

Environment:

➜ pip freeze
isort==5.0.4
➜ python --version
Python 3.8.1

[timothycrosley]

Thanks for reporting! I'm sorry this issue impacted you!
isort 5.0.5 has been released that fixes this issue with additional regression tests in place to ensure it doesn't resurface.