Issue #18279: Add tests for idlelib/RstripExtension.py. Original patch by
Phil Webster. With that available, modify RstripExtension.py to stop deleting
null slices, which caused a file to be marked as changed when it was not.
diff --git a/Misc/ACKS b/Misc/ACKS
index 087db24..b568eec 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1303,6 +1303,7 @@
 Henrik Weber
 Corran Webster
 Glyn Webster
+Phil Webster
 Stefan Wehr
 Zack Weinberg
 Bob Weiner