mu4e: implement resending

Implement the special compose type 'resend', for resending existing
messages, possibly with changes.

mu4e/mu4e-compose.el

@@ -386,10 +386,10 @@ message-thread by removing the In-Reply-To header."
   "Create a new draft message, or open an existing one.
 
 COMPOSE-TYPE determines the kind of message to compose and is a
-symbol, either `reply', `forward', `edit', `new'. `edit' is for
+symbol, either `reply', `forward', `edit', `resend' `new'. `edit'
-editing existing messages. When COMPOSE-TYPE is `reply' or
+is for editing existing (draft) messages. When COMPOSE-TYPE is
-`forward', MSG should be a message plist.  If COMPOSE-TYPE is
+`reply' or `forward', MSG should be a message plist.  If
-`new', ORIGINAL-MSG should be nil.
+COMPOSE-TYPE is `new', ORIGINAL-MSG should be nil.
 
 Optionally (when forwarding, replying) ORIGINAL-MSG is the original
 message we will forward / reply to.
@@ -406,7 +406,6 @@ tempfile)."
   (set (make-local-variable 'mu4e-compose-parent-message) original-msg)
   (put 'mu4e-compose-parent-message 'permanent-local t)
   ;; maybe switch the context
-  (message "Autoswitch")
   (mu4e~context-autoswitch mu4e-compose-parent-message
 			   mu4e-compose-context-policy)
   (run-hooks 'mu4e-compose-pre-hook)
@@ -414,7 +413,7 @@ tempfile)."
   ;; this opens (or re-opens) a messages with all the basic headers set.
   (condition-case nil
       (mu4e-draft-open compose-type original-msg)
-    (quit (kill-buffer) (message "[mu4e] Operation aborted")
+    (quit (kill-buffer) (mu4e-message "Operation aborted")
           (return-from mu4e~compose-handler)))
   ;; insert mail-header-separator, which is needed by message mode to separate
   ;; headers and body. will be removed before saving to disk
@@ -532,15 +531,15 @@ buffer."
 	    (mu4e~proc-move (match-string 1 forwarded-from) nil "+P-N")))))))
 
 (defun mu4e-compose (compose-type)
-  "Start composing a message of COMPOSE-TYPE, where COMPOSE-TYPE is
+  "Start composing a message of COMPOSE-TYPE, where COMPOSE-TYPE
-a symbol, one of `reply', `forward', `edit', `new'. All but `new'
+is a symbol, one of `reply', `forward', `edit', `resend'
-take the message at point as input. Symbol `edit' is only allowed
+`new'. All but `new' take the message at point as input. Symbol
-for draft messages."
+`edit' is only allowed for draft messages."
   (let ((msg (mu4e-message-at-point 'noerror)))
     ;; some sanity checks
     (unless (or msg (eq compose-type 'new))
       (mu4e-warn "No message at point"))
-    (unless (member compose-type '(reply forward edit new))
+    (unless (member compose-type '(reply forward edit resend new))
       (mu4e-error "Invalid compose type '%S'" compose-type))
     (when (and (eq compose-type 'edit)
 	    (not (member 'draft (mu4e-message-field msg :flags))))
@@ -584,6 +583,11 @@ draft message."
   (interactive)
   (mu4e-compose 'edit))
 
+(defun mu4e-compose-resend ()
+  "Resend the message at point in the headers buffer."
+  (interactive)
+  (mu4e-compose 'resend))
+
 (defun mu4e-compose-new ()
   "Start writing a new message."
   (interactive)

mu4e/mu4e-draft.el

@@ -402,54 +402,69 @@ fields will be the same as in the original."
   "The drafts-folder for this compose buffer, based on
 `mu4e-drafts-folder', which is evaluated once.")
 
-(defun mu4e-draft-open (compose-type &optional msg)
+(defun mu4e~draft-open-file (path)
-  "Open a draft file for a new message (when COMPOSE-TYPE is reply, forward or new),
+  "Open the the draft file at PATH."
-or open an existing draft (when COMPOSE-TYPE is edit).
+  (if (and mu4e-compose-in-new-frame (window-system))
+    (find-file-other-frame path)
+    (find-file path)))
 
-The name of the draft folder is constructed from the concatenation
+(defun mu4e~draft-determine-path (draft-dir)
-of `mu4e-maildir' and `mu4e-drafts-folder' (the latter will be
+  "Determine the path for a new draft file."
-evaluated). The message file name is a unique name determined by
+  (format "%s/%s/cur/%s"
-`mu4e-send-draft-file-name'. The initial contents will be created
+    mu4e-maildir draft-dir (mu4e~draft-message-filename-construct "DS")))
-from either `mu4e~draft-reply-construct', or
+
+
+(defun mu4e-draft-open (compose-type &optional msg)
+  "Open a draft file for a new message (when COMPOSE-TYPE is `reply', `forward' or `new'),
+open an existing draft (when COMPOSE-TYPE is `edit'), or re-send
+an existing message (when COMPOSE-TYPE is `resend').
+
+The name of the draft folder is constructed from the
+concatenation of `mu4e-maildir' and `mu4e-drafts-folder' (the
+latter will be evaluated). The message file name is a unique name
+determined by `mu4e-send-draft-file-name'. The initial contents
+will be created from either `mu4e~draft-reply-construct', or
 `mu4e~draft-forward-construct' or `mu4e~draft-newmsg-construct'."
   (unless mu4e-maildir (mu4e-error "mu4e-maildir not set"))
-  (let ((draft-dir))
+  (let ((draft-dir nil))
-    (if (eq compose-type 'edit)
+    (case compose-type
-      ;; case-1: re-editing a draft messages. in this case, we do know the full
+      
-      ;; path, but we cannot really know 'drafts folder'... we make a guess
+      (edit
-      (progn
+	;; case-1: re-editing a draft messages. in this case, we do know the full
+	;; path, but we cannot really know 'drafts folder'... we make a guess
 	(setq draft-dir (mu4e~guess-maildir (mu4e-message-field msg :path)))
-        (if (and mu4e-compose-in-new-frame (window-system))
+	(mu4e~draft-open-file (mu4e-message-field msg :path)))
-            (find-file-other-frame (mu4e-message-field msg :path))
+
-          (find-file (mu4e-message-field msg :path))))
+      (resend
-      ;; case-2: creating a new message; in this case, we can determing
+	;; case-2: copy some exisisting message to a draft message, then edit
-      ;; mu4e-get-drafts-folder
+	;; that.
-      (progn
+	(setq draft-dir (mu4e~guess-maildir (mu4e-message-field msg :path)))
+	(let ((draft-path (mu4e~draft-determine-path draft-dir)))
+	  (copy-file (mu4e-message-field msg :path) draft-path)
+	  (mu4e~draft-open-file draft-path)))
+      
+      ((reply forward new)
+	;; case-3: creating a new message; in this case, we can determing
+	;; mu4e-get-drafts-folder
 	(setq draft-dir (mu4e-get-drafts-folder msg))
-	(let ((draft-path
+	(let ((draft-path (mu4e~draft-determine-path draft-dir))
-		(format "%s/%s/cur/%s"
+	       (initial-contents
-		  mu4e-maildir
+		 (case compose-type
-		  draft-dir
+		   (reply   (mu4e~draft-reply-construct msg))
-		  (mu4e~draft-message-filename-construct "DS")))
+		   (forward (mu4e~draft-forward-construct msg))
-	      (initial-contents
+		   (new     (mu4e~draft-newmsg-construct)))))
-	       (case compose-type
+	  (mu4e~draft-open-file draft-path)
-		 (reply   (mu4e~draft-reply-construct msg))
+          (insert initial-contents) 
-		 (forward (mu4e~draft-forward-construct msg))
+	  (newline)
-		 (new     (mu4e~draft-newmsg-construct))
+	  ;; include the message signature (if it's set)
-		 (t (mu4e-error "unsupported compose-type %S" compose-type)))))
+	  (if (and mu4e-compose-signature-auto-include mu4e-compose-signature)
-	  (if (and mu4e-compose-in-new-frame (window-system))
+	    (let ((message-signature mu4e-compose-signature))
-              (find-file-other-frame draft-path)
+	      (save-excursion
-            (find-file draft-path))
+		(message-insert-signature)
-          (insert initial-contents))
+		(mu4e~fontify-signature))))))
-    (newline)
+      (t (mu4e-error "unsupported compose-type %S" compose-type)))
-	;; include the message signature (if it's set)
+      ;; evaluate mu4e~drafts-drafts-folder once, here, and use that value
-	(if (and mu4e-compose-signature-auto-include mu4e-compose-signature)
+      ;; throughout.
-	  (let ((message-signature mu4e-compose-signature))
-	    (save-excursion
-	      (message-insert-signature)
-	      (mu4e~fontify-signature))))))
-	  ;; evaluate mu4e~drafts-drafts-folder once, here, and use that value
-	  ;; throughout.
     (set (make-local-variable 'mu4e~draft-drafts-folder) draft-dir)
     (put 'mu4e~draft-drafts-folder 'permanent-local t)
     (unless mu4e~draft-drafts-folder

mu4e/mu4e-proc.el

@@ -435,13 +435,13 @@ e.g. '/drafts'.
 
 (defun mu4e~proc-compose (type decrypt &optional docid)
   "Start composing a message of certain TYPE (a symbol, either
-`forward', `reply', `edit' or `new', based on an original
+`forward', `reply', `edit', `resend' or `new', based on an
-message (ie, replying to, forwarding, editing) with DOCID or nil
+original message (ie, replying to, forwarding, editing,
-for type `new'.
+resending) with DOCID or nil for type `new'.
 
 The result will be delivered to the function registered as
 `mu4e-compose-func'."
-  (unless (member type '(forward reply edit new))
+  (unless (member type '(forward reply edit resend new))
     (mu4e-error "Unsupported compose-type %S" type))
   (unless (eq (null docid) (eq type 'new))
     (mu4e-error "`new' implies docid not-nil, and vice-versa"))