(gnus-summary-refer-thread): Implement a version that uses *-request-thread.

[gnus] / lisp / gnus-sum.el

diff --git a/lisp/gnus-sum.el b/lisp/gnus-sum.el
index 1086e28..568e297 100644 (file)
--- a/lisp/gnus-sum.el
+++ b/lisp/gnus-sum.el
@@ -8824,31 +8824,35 @@ Return the number of articles fetched."
 
 (defun gnus-summary-refer-thread (&optional limit)
   "Fetch all articles in the current thread.
-If LIMIT (the numerical prefix), fetch that many old headers instead
-of what's specified by the `gnus-refer-thread-limit' variable."
+If no backend-specific 'request-thread function is available
+fetch LIMIT (the numerical prefix) old headers. If LIMIT is nil
+fetch what's specified by the `gnus-refer-thread-limit'
+variable."
   (interactive "P")
   (let ((id (mail-header-id (gnus-summary-article-header)))
        (limit (if limit (prefix-numeric-value limit)
                 gnus-refer-thread-limit)))
-    (unless (eq gnus-fetch-old-headers 'invisible)
-      (gnus-message 5 "Fetching headers for %s..." gnus-newsgroup-name)
-      ;; Retrieve the headers and read them in.
-      (if (eq (if (numberp limit)
-                 (gnus-retrieve-headers
-                  (list (min
-                         (+ (mail-header-number
-                             (gnus-summary-article-header))
-                            limit)
-                         gnus-newsgroup-end))
-                  gnus-newsgroup-name (* limit 2))
-               ;; gnus-refer-thread-limit is t, i.e. fetch _all_
-               ;; headers.
-               (gnus-retrieve-headers (list gnus-newsgroup-end)
-                                      gnus-newsgroup-name limit))
-             'nov)
-         (gnus-build-all-threads)
-       (error "Can't fetch thread from back ends that don't support NOV"))
-      (gnus-message 5 "Fetching headers for %s...done" gnus-newsgroup-name))
+    (if  (gnus-check-backend-function 'request-thread gnus-newsgroup-name)
+       (gnus-request-thread id)
+      (unless (eq gnus-fetch-old-headers 'invisible)
+       (gnus-message 5 "Fetching headers for %s..." gnus-newsgroup-name)
+       ;;      Retrieve the headers and read them in.
+       (if (numberp limit)
+           (gnus-retrieve-headers
+            (list (min
+                   (+ (mail-header-number
+                       (gnus-summary-article-header))
+                      limit)
+                   gnus-newsgroup-end))
+            gnus-newsgroup-name (* limit 2))
+         ;; gnus-refer-thread-limit is t, i.e. fetch _all_
+         ;; headers.
+         (gnus-retrieve-headers (list gnus-newsgroup-end)
+                                gnus-newsgroup-name limit)
+         (gnus-message 5 "Fetching headers for %s...done"
+                       gnus-newsgroup-name))))
+    (when (eq gnus-headers-retrieved-by 'nov)
+      (gnus-build-all-threads))
     (gnus-summary-limit-include-thread id)))
 
 (defun gnus-summary-refer-article (message-id)