* mu4e-view.el: indent continuation header lines, so they're easier distinguishable

emacs/mu4e-view.el

@@ -140,14 +140,20 @@ marking if it still had that."
 
 (defun mu4e-view-header (key val &optional dont-propertize-val)
   "Return header KEY with value VAL if VAL is non-nil. If
-DONT-PROPERTIZE-VAL, do not add text-properties to VAL."
+DONT-PROPERTIZE-VAL is non-nil, do not add text-properties to VAL."
   (if val
     (with-temp-buffer
       (insert (propertize key 'face 'mu4e-view-header-key-face) ": "
 	(if dont-propertize-val
 	  val
 	  (propertize val 'face 'mu4e-view-header-value-face)) "\n")
+      ;; temporarily set the fill column <margin> positions to the right, so
+      ;; we can indent following lines with positions
+      (let*((margin 1) (fill-column (- fill-column margin)))
 	(fill-region (point-min) (point-max))
+	(goto-char (point-min))
+	(while (and (zerop (forward-line 1)) (not (looking-at "^$")))
+	  (indent-to-column margin)))
       (buffer-string))
     ""))
 
@@ -386,7 +392,6 @@ is nil, and otherwise open it."
   ;; esp. with '>' cited parts
   (when (fboundp 'filladapt-mode)
     (filladapt-mode))
-
   (setq truncate-lines t))