The attached patch (emacs-24 commit dated yesterday) increased the Git 
commit message line-length limit to 78 characters.  This will have 
consequences once we start generating ChangeLog files automatically from 
commit messages.  Because ChangeLog entries are indented by a tab, the 
resulting ChangeLog files will typically require 78 + 8 == 86 columns, 
not the 80 columns they have traditionally needed.  Is this 
intentional?  If not, a simple fix is to change the limit back to 72.  
If so, I suppose we could work around the problem with something like 
the following patch, though this will be more of a change to current 
practice:

diff --git a/lisp/vc/add-log.el b/lisp/vc/add-log.el
index 8e44c02..93a2ac6 100644
--- a/lisp/vc/add-log.el
+++ b/lisp/vc/add-log.el
@@ -1034,7 +1034,8 @@ the change log file in another window."
  ;;;###autoload
  (define-derived-mode change-log-mode text-mode "Change Log"
    "Major mode for editing change logs; like Indented Text mode.
-Prevents numeric backups and sets `left-margin' to 8 and `fill-column' 
to 74.
+Prevents numeric backups, and sets `left-margin' to 8, `fill-column' to 74,
+and `tab-width' to 2.
  New log entries are usually made with \\[add-change-log-entry] or 
\\[add-change-log-entry-other-window].
  Each entry behaves as a paragraph, and the entries for one day as a page.
  Runs `change-log-mode-hook'.
@@ -1042,7 +1043,7 @@ Runs `change-log-mode-hook'.
    (setq left-margin 8
      fill-column 74
      indent-tabs-mode t
-    tab-width 8
+    tab-width 2
      show-trailing-whitespace t)
    (set (make-local-variable 'fill-forward-paragraph-function)
         'change-log-fill-forward-paragraph)