Merge changes made in Gnus master

doc/misc/ChangeLog

+2013-07-08  Tassilo Horn  <tsdh@gnu.org>
+
+	* gnus.texi (lines): Correct description of
+	`gnus-registry-track-extra's default value.  Mention
+	`gnus-registry-remove-extra-data'.
+
 2013-07-06  Lars Ingebrigtsen  <larsi@gnus.org>
 
 	* gnus.texi (Group Parameters): Mention regexp

doc/misc/gnus.texi

@@ -26006,9 +26006,13 @@ following variables.
 @defvar gnus-registry-track-extra
 This is a list of symbols, so it's best to change it from the
-Customize interface.  By default it's @code{(subject sender)}, which
-may work for you.  It can be annoying if your mail flow is large and
-people don't stick to the same groups.
+Customize interface.  By default it's @code{(subject sender recipient)},
+which may work for you.  It can be annoying if your mail flow is large
+and people don't stick to the same groups.
+
+When you decide to stop tracking any of those extra data, you can use
+the command @code{gnus-registry-remove-extra-data} to purge it from
+the existing registry entries.
 @end defvar
 @defvar gnus-registry-split-strategy

lisp/gnus/ChangeLog

+2013-07-08  Lars Magne Ingebrigtsen  <larsi@gnus.org>
+
+	* nnml.el (nnml-request-compact-group): Don't bug out if we can't
+	delete files (bug#13481).
+
+2013-07-08  Tassilo Horn  <tsdh@gnu.org>
+
+	* gnus-registry.el (gnus-registry-remove-extra-data): New function.
+
 2013-07-06  Lars Ingebrigtsen  <larsi@gnus.org>
 	* gnus-art.el (gnus-block-private-groups): Allow `global' methods to

lisp/gnus/gnus-registry.el

@@ -1186,6 +1186,29 @@ data stored in the registry."
                   (gnus-select-group-with-message-id group message-id) t)
               (throw 'found t))))))))
 
+(defun gnus-registry-remove-extra-data (extra)
+  "Remove tracked EXTRA data from the gnus registry.
+EXTRA is a list of symbols.  Valid symbols are those contained in
+the docs of `gnus-registry-track-extra'.  This command is useful
+when you stop tracking some extra data and now want to purge it
+from your existing entries."
+  (interactive (list (mapcar 'intern
+			     (completing-read-multiple
+			      "Extra data: "
+			      '("subject" "sender" "recipient")))))
+  (when extra
+    (let ((db gnus-registry-db))
+      (registry-reindex db)
+      (loop for k being the hash-keys of (oref db :data)
+	    using (hash-value v)
+	    do (let ((newv (delq nil (mapcar #'(lambda (entry)
+						 (unless (member (car entry) extra)
+						   entry))
+					     v))))
+		 (registry-delete db (list k) nil)
+		 (gnus-registry-insert db k newv)))
+      (registry-reindex db))))
+
 ;; TODO: a few things
 
 (provide 'gnus-registry)

lisp/gnus/nnml.el

@@ -1094,7 +1094,10 @@ Use the nov database for the current group if available."
 		       (concat group ":" new-number-string)))
 		    ;; Save to the new file:
 		    (nnmail-write-region (point-min) (point-max) newfile))
-		  (funcall nnmail-delete-file-function oldfile))
+		  (condition-case ()
+		      (funcall nnmail-delete-file-function oldfile)
+		    (file-error
+		     (message "Couldn't delete %s" oldfile))))
 		;; 2/ Update all marks for this article:
 		;; #### NOTE: it is possible that the new article number
 		;; #### already belongs to a range, whereas the corresponding