1 files changed, 96 insertions, 30 deletions
diff --git a/lisp/gnus/gnus-cache.el b/lisp/gnus/gnus-cache.el
index 9423d9f2f6b..36657e46219 100644
--- a/lisp/gnus/gnus-cache.el
+++ b/lisp/gnus/gnus-cache.el
@@ -294,47 +294,49 @@ it's not cached."
 (defun gnus-cache-retrieve-headers (articles group &optional fetch-old)
   "Retrieve the headers for ARTICLES in GROUP."
   (let ((cached
-	 (setq gnus-newsgroup-cached (gnus-cache-articles-in-group group)))
-	(gnus-newsgroup-name group)
-	(gnus-fetch-old-headers fetch-old))
+	 (setq gnus-newsgroup-cached (gnus-cache-articles-in-group group))))
     (if (not cached)
 	;; No cached articles here, so we just retrieve them
 	;; the normal way.
 	(let ((gnus-use-cache nil))
-	  (gnus-retrieve-headers articles group))
+	  (gnus-retrieve-headers articles group fetch-old))
       (let ((uncached-articles (gnus-sorted-difference articles cached))
 	    (cache-file (gnus-cache-file-name group ".overview"))
-	    (file-name-coding-system nnmail-pathname-coding-system)
-	    headers)
+	    type
+	    (file-name-coding-system nnmail-pathname-coding-system))
 	;; We first retrieve all the headers that we don't have in
 	;; the cache.
 	(let ((gnus-use-cache nil))
 	  (when uncached-articles
-	    (setq headers (and articles
-			       (gnus-fetch-headers uncached-articles)))))
+	    (setq type (and articles
+			    (gnus-retrieve-headers
+			     uncached-articles group fetch-old)))))
 	(gnus-cache-save-buffers)
-	;; Then we include the cached headers.
-	(when (file-exists-p cache-file)
-	  (setq headers
-		(delete-dups
-		 (sort
-		  (append headers
-			  (let ((coding-system-for-read
-				 gnus-cache-overview-coding-system))
-			    (with-current-buffer nntp-server-buffer
-			      (erase-buffer)
-			      (insert-file-contents cache-file)
-			      (gnus-get-newsgroup-headers-xover
-			       (gnus-sorted-difference
-				cached uncached-articles)
-			       nil (buffer-local-value
-				    'gnus-newsgroup-dependencies
-				    gnus-summary-buffer)
-			       group))))
-		  (lambda (l r)
-		    (< (mail-header-number l)
-		       (mail-header-number r)))))))
-	headers))))
+	;; Then we insert the cached headers.
+	(save-excursion
+	  (cond
+	   ((not (file-exists-p cache-file))
+	    ;; There are no cached headers.
+	    type)
+	   ((null type)
+	    ;; There were no uncached headers (or retrieval was
+	    ;; unsuccessful), so we use the cached headers exclusively.
+	    (set-buffer nntp-server-buffer)
+	    (erase-buffer)
+	    (let ((coding-system-for-read
+		   gnus-cache-overview-coding-system))
+	      (insert-file-contents cache-file))
+	    'nov)
+	   ((eq type 'nov)
+	    ;; We have both cached and uncached NOV headers, so we
+	    ;; braid them.
+	    (gnus-cache-braid-nov group cached)
+	    type)
+	   (t
+	    ;; We braid HEADs.
+	    (gnus-cache-braid-heads group (gnus-sorted-intersection
+					   cached articles))
+	    type)))))))
 
 (defun gnus-cache-enter-article (&optional n)
   "Enter the next N articles into the cache.
@@ -527,6 +529,70 @@ Returns the list of articles removed."
 	  (setq gnus-cache-active-altered t)))
       articles)))
 
+(defun gnus-cache-braid-nov (group cached &optional file)
+  (let ((cache-buf (gnus-get-buffer-create " *gnus-cache*"))
+	beg end)
+    (gnus-cache-save-buffers)
+    (with-current-buffer cache-buf
+      (erase-buffer)
+      (let ((coding-system-for-read gnus-cache-overview-coding-system)
+	    (file-name-coding-system nnmail-pathname-coding-system))
+	(insert-file-contents
+	 (or file (gnus-cache-file-name group ".overview"))))
+      (goto-char (point-min))
+      (insert "\n")
+      (goto-char (point-min)))
+    (set-buffer nntp-server-buffer)
+    (goto-char (point-min))
+    (while cached
+      (while (and (not (eobp))
+		  (< (read (current-buffer)) (car cached)))
+	(forward-line 1))
+      (beginning-of-line)
+      (set-buffer cache-buf)
+      (if (search-forward (concat "\n" (int-to-string (car cached)) "\t")
+			  nil t)
+	  (setq beg (point-at-bol)
+		end (progn (end-of-line) (point)))
+	(setq beg nil))
+      (set-buffer nntp-server-buffer)
+      (when beg
+	(insert-buffer-substring cache-buf beg end)
+	(insert "\n"))
+      (setq cached (cdr cached)))
+    (kill-buffer cache-buf)))
+
+(defun gnus-cache-braid-heads (group cached)
+  (let ((cache-buf (gnus-get-buffer-create " *gnus-cache*")))
+    (with-current-buffer cache-buf
+      (erase-buffer))
+    (set-buffer nntp-server-buffer)
+    (goto-char (point-min))
+    (dolist (entry cached)
+      (while (and (not (eobp))
+		  (looking-at "2.. +\\([0-9]+\\) ")
+		  (< (progn (goto-char (match-beginning 1))
+			    (read (current-buffer)))
+		     entry))
+	(search-forward "\n.\n" nil 'move))
+      (beginning-of-line)
+      (set-buffer cache-buf)
+      (erase-buffer)
+      (let ((coding-system-for-read gnus-cache-coding-system)
+	    (file-name-coding-system nnmail-pathname-coding-system))
+	(insert-file-contents (gnus-cache-file-name group entry)))
+      (goto-char (point-min))
+      (insert "220 ")
+      (princ (pop cached) (current-buffer))
+      (insert " Article retrieved.\n")
+      (search-forward "\n\n" nil 'move)
+      (delete-region (point) (point-max))
+      (forward-char -1)
+      (insert ".")
+      (set-buffer nntp-server-buffer)
+      (insert-buffer-substring cache-buf))
+    (kill-buffer cache-buf)))
+
 ;;;###autoload
 (defun gnus-jog-cache ()
   "Go through all groups and put the articles into the cache.