emacs-28 43ed7b1e0f: ; Update instructions about ChangeLog.N file generation

[Eli Zaretskii]

branch: emacs-28
commit 43ed7b1e0f182a5f4d82f6542ebf4308d0f78fc5
Author: Eli Zaretskii <eliz@gnu.org>
Commit: Eli Zaretskii <eliz@gnu.org>

    ; Update instructions about ChangeLog.N file generation
    
    * admin/make-tarball.txt: Add instructions about rotating and
    regenerating the versioned ChangeLog.N file.
---
 admin/make-tarball.txt | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/admin/make-tarball.txt b/admin/make-tarball.txt
index 17a4d9f807..436a0957c0 100644
--- a/admin/make-tarball.txt
+++ b/admin/make-tarball.txt
@@ -54,12 +54,31 @@ General steps (for each step, check for possible errors):
     section at the beginning of that file, and commit etc/NEWS if it
     was modified.
 
-2.  Regenerate the etc/AUTHORS file:
+2.  Regenerate the versioned ChangeLog.N and etc/AUTHORS files.
+
+    The "M-x authors" command below will first update the current
+    versioned ChangeLog.N file.  For this to work correctly, make sure
+    the top-level Makefile says
+
+      PREFERRED_BRANCH = emacs-NN
+
+    where NN is the version on the release branch from which you are
+    producing the tarball.  If NN is incorrect, update Makefile.in and
+    re-run 'configure' to update Makefile.
+
+    If the versioned ChangeLog.N file is too large, start a new one
+    by bumping N, and also update the line in top-level Makefile.in
+    which says
+
+      CHANGELOG_HISTORY_INDEX_MAX = N
+
+    by incrementing the value of N by 1; then regenerate Makefile.
+
+    Now:
+
       M-: (require 'authors) RET
       M-x authors RET
 
-    (This first updates the current versioned ChangeLog.N)
-
     If this says "Problem updating ChangeLog", find the reason for the
     failure of the command it runs, viz.: