+ "Compose a reply to the message identified by QUERY-STRING.
+
+If PROMPT-FOR-SENDER is non-nil, the user will be prompted for
+the From: address first. If REPLY-ALL is non-nil, the message
+will be addressed to all recipients of the source message."
+
+;; In current emacs (24.3) select-active-regions is set to t by
+;; default. The reply insertion code sets the region to the quoted
+;; message to make it easy to delete (kill-region or C-w). These two
+;; things combine to put the quoted message in the primary selection.
+;;
+;; This is not what the user wanted and is a privacy risk (accidental
+;; pasting of the quoted message). We can avoid some of the problems
+;; by let-binding select-active-regions to nil. This fixes if the
+;; primary selection was previously in a non-emacs window but not if
+;; it was in an emacs window. To avoid the problem in the latter case
+;; we deactivate mark.
+