Fix regression with distutils MANIFEST handing (#11104, #8688).

The changed behavior of sdist in 2.7 broke packaging for projects that
wanted to use a manually-maintained MANIFEST file (instead of having a
MANIFEST.in template and letting distutils generate the MANIFEST).

The fixes that were committed for #8688 (d29399100973 by Tarek and
f7639dcdffc3 by me) did not fix all issues exposed in the bug report,
and also added one problem: the MANIFEST file format gained comments,
but the read_manifest method was not updated to handle (i.e. ignore)
them.  This changeset should fix everything; the tests have been
expanded and I successfully tested with Mercurial, which suffered from
this regression.

I have grouped the versionchanged directives for these bugs in one place
and added micro version numbers to help users know the quirks of the
exact version they’re using.  I also removed a stanza in the docs that
was forgotten in Tarek’s first changeset.

Initial report, thorough diagnosis and patch by John Dennis, further
work on the patch by Stephen Thorne, and a few edits and additions by
me.

2 files changed, 5 insertions, 0 deletions

diff --git a/Misc/ACKS b/Misc/ACKS
index bfbbf69..ff0a29a 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -194,6 +194,7 @@ Ned Deily
 Vincent Delft
 Arnaud Delobelle
 Erik Demaine
+John Dennis
 Roger Dev
 Raghuram Devarakonda
 Catherine Devlin
@@ -813,6 +814,7 @@ Mikhail Terekhov
 Tobias Thelen
 James Thomas
 Robin Thomas
+Stephen Thorne
 Eric Tiedemann
 Tracy Tims
 Oren Tirosh
diff --git a/Misc/NEWS b/Misc/NEWS
index fc4dfe9..0aeddf4 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -37,6 +37,9 @@ Core and Builtins
 Library
 -------
 
+- Issues #11104, #8688: Fix the behavior of distutils' sdist command with
+  manually-maintained MANIFEST files.
+
 - Issue #8887: "pydoc somebuiltin.somemethod" (or help('somebuiltin.somemethod')
   in Python code) now finds the doc of the method.