* mu4e/crypto: support mu4e-decryption-policy

mu4e/mu4e-headers.el

@@ -1107,12 +1107,18 @@ current window. "
     (mu4e-error "Must be in mu4e-headers-mode (%S)" major-mode))
   (let* ((docid (or (mu4e~headers-docid-at-point)
 		  (mu4e-warn "No message at point")))
+	  ;; decrypt (or not), based on `mu4e-decryption-policy'.
+	  (decrypt
+	    (and (member 'encrypted (mu4e-field-at-point :flags))
+	      (if (eq mu4e-decryption-policy 'ask)
+		(yes-or-no-p (mu4e-format "Decrypt message?"))
+		mu4e-decryption-policy)))  
 	  (viewwin (mu4e~headers-redraw-get-view-window)))
     (unless (window-live-p viewwin)
       (mu4e-error "Cannot get a message view"))
     (select-window viewwin)
     (switch-to-buffer (mu4e~headers-get-loading-buf))
-    (mu4e~proc-view docid mu4e-show-images)))
+    (mu4e~proc-view docid mu4e-show-images decrypt)))
 
 (defun mu4e-headers-rerun-search ()
   "Rerun the search for the last search expression."

mu4e/mu4e-proc.el

@@ -456,17 +456,17 @@ seen AFTER (the time_t value)."
     (if personal "true" "false")
     (or after 0)))
 
-(defun mu4e~proc-view (docid-or-msgid &optional images)
+(defun mu4e~proc-view (docid-or-msgid &optional images decrypt)
   "Get one particular message based on its DOCID-OR-MSGID (keyword
 argument). Optionally, if IMAGES is non-nil, backend will any
 images attached to the message, and return them as temp files.  The
 result will be delivered to the function registered as
 `mu4e-message-func'."
   (mu4e~proc-send-command
-    "view %s extract-images:%s extract-encrypted:true"
+    "view %s extract-images:%s extract-encrypted:%s"
     (mu4e--docid-msgid-param docid-or-msgid)
-    (if images "true" "false")))
+    (if images "true" "false")
+    (if decrypt "true" "false")))
 
 (provide 'mu4e-proc)
-
 ;; End of mu4e-proc.el

mu4e/mu4e-vars.el

@@ -157,14 +157,14 @@ view buffer."
   :type 'boolean
   :group 'mu4e-crypto)
 
-(defcustom mu4e-decryption-policy 'auto
+(defcustom mu4e-decryption-policy t
   "Policy for dealing with encrypted parts. The setting is a symbol:
- * `auto': try to decrypt automatically
+ * t:     try to decrypt automatically
  * `ask': ask before decrypting anything
- * `no': don't try to decrypt anything."
+ * nil:   don't try to decrypt anything."
-  :type '(choice (const :tag "Try to decrypt automatically" auto)
+  :type '(choice (const :tag "Try to decrypt automatically" t)
                  (const :tag "Ask before decrypting anything" ask)
-                 (const :tag "Don't try to decrypt anything" no))
+                 (const :tag "Don't try to decrypt anything" nil))
   :group 'mu4e-crypto)
 
 ;; completion; we put them here rather than in mu4e-compose, as mu4e-utils needs

mu4e/mu4e-view.el

@@ -138,12 +138,15 @@ The first letter of NAME is used as a shortcut character.")
   "A mapping of user-visible attachment number to the actual part index.")
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
-
-
 (defun mu4e-view-message-with-msgid (msgid)
   "View message with MSGID. This is meant for external programs
 wanting to show specific messages - for example, `mu4e-org'."
-  (mu4e~proc-view msgid mu4e-show-images))
+  ;; note: hackish; if mu4e-decryption-policy is non-nil (ie., t or 'ask), we
+  ;; decrpt the message. Since here we don't know if message is encrypted or
+  ;; not, when the policy is 'ask'. we simply assume the user said yes...  the
+  ;; alternative would be to ask for each message, encrypted or not.  maybe we
+  ;; need an extra policy...
+  (mu4e~proc-view msgid mu4e-show-images mu4e-decryption-policy))
 
 (defun mu4e-view-message-text (msg)
   "Return the message to display (as a string), based on the MSG