+(defun gnus-summary-limit-to-address (address &optional not-matching)
+ "Limit the summary buffer to articles with the given ADDRESS.
+
+If NOT-MATCHING, exclude ADDRESS.
+
+To, Cc and From headers are checked. You need to include `To' and `Cc'
+in `nnmail-extra-headers'."
+ (interactive
+ (list (read-string (format "%s address (regexp): "
+ (if current-prefix-arg "Exclude" "Limit to")))
+ current-prefix-arg))
+ (when (not (equal "" address))
+ (prog1 (let* ((to
+ (if (memq 'To nnmail-extra-headers)
+ (gnus-summary-find-matching
+ (cons 'extra 'To) address 'all nil nil
+ not-matching)
+ (gnus-message
+ 1 "`To' isn't present in `nnmail-extra-headers'")
+ (sit-for 1)
+ t))
+ (cc
+ (if (memq 'Cc nnmail-extra-headers)
+ (gnus-summary-find-matching
+ (cons 'extra 'Cc) address 'all nil nil
+ not-matching)
+ (gnus-message
+ 1 "`Cc' isn't present in `nnmail-extra-headers'")
+ (sit-for 1)
+ t))
+ (from
+ (gnus-summary-find-matching "from" address
+ 'all nil nil not-matching))
+ (articles
+ (if not-matching
+ ;; We need the numbers that are in all lists:
+ (if (eq cc t)
+ (if (eq to t)
+ from
+ (mapcar (lambda (a) (car (memq a from))) to))
+ (if (eq to t)
+ (mapcar (lambda (a) (car (memq a from))) cc)
+ (mapcar (lambda (a) (car (memq a from)))
+ (mapcar (lambda (a) (car (memq a to)))
+ cc))))
+ (nconc (if (eq to t) nil to)
+ (if (eq cc t) nil cc)
+ from))))
+ (unless articles
+ (error "Found no matches for \"%s\"" address))
+ (gnus-summary-limit articles))
+ (gnus-summary-position-point))))
+
+(defun gnus-summary-limit-strange-charsets-predicate (header)
+ (let ((string (concat (mail-header-subject header)
+ (mail-header-from header)))
+ charset found)
+ (dotimes (i (1- (length string)))
+ (setq charset (format "%s" (char-charset (aref string (1+ i)))))
+ (when (string-match "unicode\\|big\\|japanese" charset)
+ (setq found t)))
+ found))
+
+(defun gnus-summary-limit-to-predicate (predicate)
+ "Limit to articles where PREDICATE returns non-nil.
+PREDICATE will be called with the header structures of the
+articles."
+ (let ((articles nil)
+ (case-fold-search t))
+ (dolist (header gnus-newsgroup-headers)
+ (when (funcall predicate header)
+ (push (mail-header-number header) articles)))
+ (gnus-summary-limit (nreverse articles))))
+