bug#34908: Push mark in xref-push-marker-stack

[Juri Linkov]

X-Debbugs-CC: João Távora <joaotavora@gmail.com>, Dmitry Gutov 
<dgutov@yandex.ru>

Shouldn't xref-push-marker-stack push the mark like all normal commands do?

I know there is ‘M-,’ but why not allow using the standard keys
‘C-x C-SPC’ (pop-global-mark) and ‘C-u C-SPC’ (in the same file)
as well?

diff --git a/lisp/progmodes/xref.el b/lisp/progmodes/xref.el
index 6974d00048..861e24a85f 100644
--- a/lisp/progmodes/xref.el
+++ b/lisp/progmodes/xref.el
@@ -365,6 +365,7 @@ xref-set-marker-ring-length
 
 (defun xref-push-marker-stack (&optional m)
   "Add point M (defaults to `point-marker') to the marker stack."
+  (push-mark nil t)
   (ring-insert xref--marker-ring (or m (point-marker))))