(query-replace-show-replacement): New defcustom.

[bpt/emacs.git] / lisp / replace.el

diff --git a/lisp/replace.el b/lisp/replace.el
index 5fe8ad4..7876f9b 100644 (file)
--- a/lisp/replace.el
+++ b/lisp/replace.el
@@ -69,6 +69,12 @@ strings or patterns."
   :group 'matching
   :version "22.1")
 
+(defcustom query-replace-show-replacement t
+  "*Non-nil means to show what actual replacement text will be."
+  :type 'boolean
+  :group 'matching
+  :version "23.1")
+
 (defcustom query-replace-highlight t
   "*Non-nil means to highlight matches during query replacement."
   :type 'boolean
@@ -1570,10 +1576,17 @@ make, or the user didn't cancel the call."
                   (or delimited-flag regexp-flag) case-fold-search)
                  ;; Bind message-log-max so we don't fill up the message log
                  ;; with a bunch of identical messages.
-                 (let ((message-log-max nil))
+                 (let ((message-log-max nil)
+                       (replacement-presentation
+                        (if query-replace-show-replacement
+                            (save-match-data
+                              (set-match-data real-match-data)
+                              (match-substitute-replacement next-replacement
+                                                            nocasify literal))
+                          next-replacement)))
                    (message message
                              (query-replace-descr from-string)
-                             (query-replace-descr next-replacement)))
+                             (query-replace-descr replacement-presentation)))
                  (setq key (read-event))
                  ;; Necessary in case something happens during read-event
                  ;; that clobbers the match data.