New customization variable: Loop over headlines in active region

* org.el (org-loop-over-headlines-in-active-region): New customization
variable. Loop over headlines in active region.
(org-schedule, org-deadline): Apply to headlines in region depending
on new customization variable.

lisp/org.el

@@ -403,6 +403,25 @@ XEmacs user should have this variable set to nil, because
 	  (const :tag "When outside special context" t)
 	  (const :tag "Everywhere except timestamps" always)))
 
+(defcustom org-loop-over-headlines-in-active-region nil
+  "Shall some commands act upon headlines in the active region?
+
+When set to `t', some commands will be performed in all headlines
+within the active region.
+
+When set to a string, those commands will be performed on the
+matching headlines within the active region.  Such string must be
+a tags/property/todo match as it is used in the agenda tags view.
+
+The list of commands is:
+- `org-schedule'
+- `org-deadline'"
+  :type '(choice (const :tag "Don't loop" nil)
+		 (const :tag "All headlines in active region" t)
+		 (string :tag "Tags/Property/Todo matcher"))
+  :group 'org-todo
+  :group 'org-archive)
+
 (defgroup org-startup nil
   "Options concerning startup of Org-mode."
   :tag "Org Startup"
@@ -11851,39 +11870,43 @@ With argument REMOVE, remove any deadline from the item.
 With argument TIME, set the deadline at the corresponding date.  TIME
 can either be an Org date like \"2011-07-24\" or a delta like \"+2d\"."
   (interactive "P")
-  (let* ((old-date (org-entry-get nil "DEADLINE"))
-	 (repeater (and old-date
-			(string-match
-			 "\\([.+-]+[0-9]+[dwmy]\\(?:[/ ][-+]?[0-9]+[dwmy]\\)?\\) ?"
-			  old-date)
-			(match-string 1 old-date))))
-    (if remove
-	(progn
-	  (when (and old-date org-log-redeadline)
-	    (org-add-log-setup 'deldeadline nil old-date 'findpos
-			       org-log-redeadline))
-	  (org-remove-timestamp-with-keyword org-deadline-string)
-	  (message "Item no longer has a deadline."))
-      (org-add-planning-info 'deadline time 'closed)
-      (when (and old-date org-log-redeadline
-		 (not (equal old-date
-			     (substring org-last-inserted-timestamp 1 -1))))
-	(org-add-log-setup 'redeadline nil old-date 'findpos
-			   org-log-redeadline))
-      (when repeater
-	(save-excursion
-	  (org-back-to-heading t)
-	  (when (re-search-forward (concat org-deadline-string " "
-					   org-last-inserted-timestamp)
-				   (save-excursion
-				     (outline-next-heading) (point)) t)
-	    (goto-char (1- (match-end 0)))
-	    (insert " " repeater)
-	    (setq org-last-inserted-timestamp
-		  (concat (substring org-last-inserted-timestamp 0 -1)
-			  " " repeater
-			  (substring org-last-inserted-timestamp -1))))))
-      (message "Deadline on %s" org-last-inserted-timestamp))))
+  (if (and (org-region-active-p) org-loop-over-headlines-in-active-region)
+      (let (org-loop-over-headlines-in-active-region)
+	(org-map-entries
+	 `(org-deadline ',remove ,time) org-loop-over-headlines-in-active-region 'region))
+    (let* ((old-date (org-entry-get nil "DEADLINE"))
+	   (repeater (and old-date
+			  (string-match
+			   "\\([.+-]+[0-9]+[dwmy]\\(?:[/ ][-+]?[0-9]+[dwmy]\\)?\\) ?"
+			   old-date)
+			  (match-string 1 old-date))))
+      (if remove
+	  (progn
+	    (when (and old-date org-log-redeadline)
+	      (org-add-log-setup 'deldeadline nil old-date 'findpos
+				 org-log-redeadline))
+	    (org-remove-timestamp-with-keyword org-deadline-string)
+	    (message "Item no longer has a deadline."))
+	(org-add-planning-info 'deadline time 'closed)
+	(when (and old-date org-log-redeadline
+		   (not (equal old-date
+			       (substring org-last-inserted-timestamp 1 -1))))
+	  (org-add-log-setup 'redeadline nil old-date 'findpos
+			     org-log-redeadline))
+	(when repeater
+	  (save-excursion
+	    (org-back-to-heading t)
+	    (when (re-search-forward (concat org-deadline-string " "
+					     org-last-inserted-timestamp)
+				     (save-excursion
+				       (outline-next-heading) (point)) t)
+	      (goto-char (1- (match-end 0)))
+	      (insert " " repeater)
+	      (setq org-last-inserted-timestamp
+		    (concat (substring org-last-inserted-timestamp 0 -1)
+			    " " repeater
+			    (substring org-last-inserted-timestamp -1))))))
+	(message "Deadline on %s" org-last-inserted-timestamp)))))
 
 (defun org-schedule (&optional remove time)
   "Insert the SCHEDULED: string with a timestamp to schedule a TODO item.
@@ -11891,39 +11914,43 @@ With argument REMOVE, remove any scheduling date from the item.
 With argument TIME, scheduled at the corresponding date.  TIME can
 either be an Org date like \"2011-07-24\" or a delta like \"+2d\"."
   (interactive "P")
-  (let* ((old-date (org-entry-get nil "SCHEDULED"))
-	 (repeater (and old-date
-			(string-match
-			 "\\([.+-]+[0-9]+[dwmy]\\(?:[/ ][-+]?[0-9]+[dwmy]\\)?\\) ?"
-			 old-date)
-			(match-string 1 old-date))))
-    (if remove
-	(progn
-	  (when (and old-date org-log-reschedule)
-	    (org-add-log-setup 'delschedule nil old-date 'findpos
-			       org-log-reschedule))
-	  (org-remove-timestamp-with-keyword org-scheduled-string)
-	  (message "Item is no longer scheduled."))
-      (org-add-planning-info 'scheduled time 'closed)
-      (when (and old-date org-log-reschedule
-		 (not (equal old-date
-			     (substring org-last-inserted-timestamp 1 -1))))
-	(org-add-log-setup 'reschedule nil old-date 'findpos
-			   org-log-reschedule))
-      (when repeater
-	(save-excursion
-	  (org-back-to-heading t)
-	  (when (re-search-forward (concat org-scheduled-string " "
-					   org-last-inserted-timestamp)
-				   (save-excursion
-				     (outline-next-heading) (point)) t)
-	    (goto-char (1- (match-end 0)))
-	    (insert " " repeater)
-	    (setq org-last-inserted-timestamp
-		  (concat (substring org-last-inserted-timestamp 0 -1)
-			  " " repeater
-			  (substring org-last-inserted-timestamp -1))))))
-      (message "Scheduled to %s" org-last-inserted-timestamp))))
+  (if (and (org-region-active-p) org-loop-over-headlines-in-active-region)
+      (let (org-loop-over-headlines-in-active-region)
+	(org-map-entries
+	 `(org-schedule ',remove ,time) org-loop-over-headlines-in-active-region 'region))
+    (let* ((old-date (org-entry-get nil "SCHEDULED"))
+	   (repeater (and old-date
+			  (string-match
+			   "\\([.+-]+[0-9]+[dwmy]\\(?:[/ ][-+]?[0-9]+[dwmy]\\)?\\) ?"
+			   old-date)
+			  (match-string 1 old-date))))
+      (if remove
+	  (progn
+	    (when (and old-date org-log-reschedule)
+	      (org-add-log-setup 'delschedule nil old-date 'findpos
+				 org-log-reschedule))
+	    (org-remove-timestamp-with-keyword org-scheduled-string)
+	    (message "Item is no longer scheduled."))
+	(org-add-planning-info 'scheduled time 'closed)
+	(when (and old-date org-log-reschedule
+		   (not (equal old-date
+			       (substring org-last-inserted-timestamp 1 -1))))
+	  (org-add-log-setup 'reschedule nil old-date 'findpos
+			     org-log-reschedule))
+	(when repeater
+	  (save-excursion
+	    (org-back-to-heading t)
+	    (when (re-search-forward (concat org-scheduled-string " "
+					     org-last-inserted-timestamp)
+				     (save-excursion
+				       (outline-next-heading) (point)) t)
+	      (goto-char (1- (match-end 0)))
+	      (insert " " repeater)
+	      (setq org-last-inserted-timestamp
+		    (concat (substring org-last-inserted-timestamp 0 -1)
+			    " " repeater
+			    (substring org-last-inserted-timestamp -1))))))
+	(message "Scheduled to %s" org-last-inserted-timestamp)))))
 
 (defun org-get-scheduled-time (pom &optional inherit)
   "Get the scheduled time as a time tuple, of a format suitable