Use a marker in generated MANIFEST files, don't touch files without it. Fixes #8688.
diff --git a/Misc/NEWS b/Misc/NEWS
index 3388aec..2afb99a 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -83,6 +83,10 @@
Library
-------
+- Issue #8688: MANIFEST files created by distutils now include a magic
+ comment indicating they are generated. Manually maintained MANIFESTs
+ without this marker will not be overwritten or removed.
+
- Issue #7467: when reading a file from a ZIP archive, its CRC is checked
and a BadZipfile error is raised if it doesn't match (as used to be the
case in Python 2.5 and earlier).