master ee11a68: Remove ephemeral group on error or null result

[Andrew G Cohen]

branch: master
commit ee11a68320eeb8bb90ded9773c02d7863abca3d7
Author: Andrew G Cohen <cohen@andy.bu.edu>
Commit: Andrew G Cohen <cohen@andy.bu.edu>

    Remove ephemeral group on error or null result
    
    * lisp/gnus/nnselect.el (nnselect-request-group): If an ephemeral
    group is empty, there is nothing to see, so remove the group.
    (nnselect-run): Catch and return an empty artlist on error.
---
 lisp/gnus/nnselect.el | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/lisp/gnus/nnselect.el b/lisp/gnus/nnselect.el
index ce2e99d..e4753fe 100644
--- a/lisp/gnus/nnselect.el
+++ b/lisp/gnus/nnselect.el
@@ -295,6 +295,10 @@ If this variable is nil, or if the provided function 
returns nil,
     (if (zerop (setq length (nnselect-artlist-length nnselect-artlist)))
        (progn
          (nnheader-report 'nnselect "Selection produced empty results.")
+         (when (gnus-ephemeral-group-p group)
+           (gnus-kill-ephemeral-group group)
+           (setq gnus-ephemeral-servers
+                 (assq-delete-all 'nnselect gnus-ephemeral-servers)))
          (nnheader-insert ""))
       (with-current-buffer nntp-server-buffer
        (nnheader-insert "211 %d %d %d %s\n"
@@ -769,8 +773,10 @@ If this variable is nil, or if the provided function 
returns nil,
 Return an article list."
   (let ((func (alist-get 'nnselect-function specs))
        (args (alist-get 'nnselect-args specs)))
-    (funcall func args)))
-
+    (condition-case err
+       (funcall func args)
+      (error (gnus-error 3 "nnselect-run: %s on %s gave error %s" func args 
err)
+            []))))
 
 (defun nnselect-search-thread (header)
   "Make an nnselect group containing the thread with article HEADER.