Here come five patches for this issue, based on emacs-29:

0001-Always-erase-log-buffer-before-calling-vc-print-log.patch
0002-Always-erase-log-buffer-before-calling-vc-print-log.patch
0003-Always-erase-log-buffer-before-calling-vc-print-log.patch

   Name should be self-explaining, patches uncritical.

0004-Fix-documentation-bug-and-remove-obsolete-fixmes.patch

   `vc-deduce-fileset' uses `with-current-buffer' to protect the current
   buffer, which has not been reflected in comments.

0005-Avoid-setting-circular-vc-parent-buffer.patch

   This one fixes the issue related to VC parent buffer described in the
   previous update.  The "local" change seems to be logical (a buffer
   should not be the VC parent buffer of itself), but I'm not quite sure
   about any adverse "global" consequences.