Subject: 27.0.50; xref-find-definitions wastes too much space

From: Juri Linkov <[email-masked]>
Date: Sun, 06 Jan 2019 01:43:35 +0200

Tags: patch
Severity: wishlist
X-Debbugs-CC: João Távora <[email-masked]>, Dmitry Gutov <[email-masked]>

As noted in bug#33870 the buffer produced by xref-find-definitions
(bound to ‘M-.’) has a transient nature like the *Completions* buffer.
Therefore it makes sense not to waste its space needlessly:

diff --git a/lisp/progmodes/xref.el b/lisp/progmodes/xref.el
index 87ce2299c5..169f49a348 100644
--- a/lisp/progmodes/xref.el
+++ b/lisp/progmodes/xref.el
@@ -782,7 +773,7 @@ xref--show-xref-buffer
         (erase-buffer)
         (xref--insert-xrefs xref-alist)
         (xref--xref-buffer-mode)
-        (pop-to-buffer (current-buffer))
+        (pop-to-buffer (current-buffer) (assoc-default 'display-action-alist alist))
         (goto-char (point-min))
         (setq xref--original-window (assoc-default 'window alist)
               xref--original-window-intent (assoc-default 'display-action alist))
@@ -808,12 +799,15 @@ xref--show-xrefs
   (cond
    ((and (not (cdr xrefs)) (not always-show-list))
     (xref-push-marker-stack)
-    (xref--pop-to-location (car xrefs) display-action))
+    (xref--pop-to-location (car xrefs) (unless (listp display-action) display-action)))
    (t
     (xref-push-marker-stack)
     (funcall xref-show-xrefs-function xrefs
              `((window . ,(selected-window))
-               (display-action . ,display-action))))))
+               (display-action
+                . ,(unless (listp display-action) display-action))
+               (display-action-alist
+                . ,(when (listp display-action) display-action)))))))
 
 (defun xref--prompt-p (command)
   (or (eq xref-prompt-for-identifier t)
@@ -864,7 +858,7 @@ xref-find-definitions
 Otherwise, display the list of the possible definitions in a
 buffer where the user can select from the list."
   (interactive (list (xref--read-identifier "Find definitions of: ")))
-  (xref--find-definitions identifier nil))
+  (xref--find-definitions identifier '((display-buffer-maybe-below-selected))))
 
 ;;;###autoload
 (defun xref-find-definitions-other-window (identifier)