emacs-27 0399cc2 1/2: Erase the buffer only after fetching the new contents

[Dmitry Gutov]

branch: emacs-27
commit 0399cc2ab5cc64129d7e9030db7db76689e3a095
Author: Dmitry Gutov <dgutov@yandex.ru>
Commit: Dmitry Gutov <dgutov@yandex.ru>

    Erase the buffer only after fetching the new contents
    
    * lisp/progmodes/xref.el (xref-revert-buffer):
    Erase the buffer only after fetching the new contents (bug#46042).
    
    (cherry picked from commit 5821dee0949b2913c07970d6e4b8bb8e8a35f036)
---
 lisp/progmodes/xref.el | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lisp/progmodes/xref.el b/lisp/progmodes/xref.el
index e55d295..7f5e76c 100644
--- a/lisp/progmodes/xref.el
+++ b/lisp/progmodes/xref.el
@@ -876,10 +876,10 @@ Return an alist of the form ((FILENAME . (XREF ...)) 
...)."
   (let ((inhibit-read-only t)
         (buffer-undo-list t))
     (save-excursion
-      (erase-buffer)
       (condition-case err
-          (xref--insert-xrefs
-           (xref--analyze (funcall xref--fetcher)))
+          (let ((alist (xref--analyze (funcall xref--fetcher))))
+            (erase-buffer)
+            (xref--insert-xrefs alist))
         (user-error
          (insert
           (propertize