bug#35624: log-view-diff regression

[Juri Linkov]

>> Here is a new patch that works also for single-file logs.  It relies
>> on the function 'log-view-end-of-defun' that takes care about the
>> "Show 2X entries" footer:
>
> Looks good. Please install when you're comfortable with it.

Pushed to master.

But there is another regression.  Do you remember that in older versions
there was a header in the *vc-change-log* buffer?  It was very useful to
put the beginning of the region on the first non-revision line in the header
to compare the current working revision with the last committed revision.

Now this feature is gone, and the first line can't be used to compare
with the working revision because now the first line contains the last
committed revision.

This patch restores this useful feature:

diff --git a/lisp/vc/vc-git.el b/lisp/vc/vc-git.el
index 192e6cf68f..040b0832be 100644
--- a/lisp/vc/vc-git.el
+++ b/lisp/vc/vc-git.el
@@ -1017,8 +1017,8 @@ vc-git-print-log
     ;; If the buffer exists from a previous invocation it might be
     ;; read-only.
     (let ((inhibit-read-only t))
-      (with-current-buffer
-          buffer
+      (with-current-buffer buffer
+       (insert "Working\n")
        (apply 'vc-git-command buffer
               'async files
               (append