emacs: Add a notmuch-saved-searches function.

We use this function to abstract away the common 3-step process for
looking for a value for the saved-searches variable:

	1. Look at the notmuch-saved-searches variable itself
	2. Look at the notmuch-folders vaiable
	3. Use a default value

We were already using this logic (open-coded) in notmuch-hello, but
notmuch.el was accessing notmuch-folders directly for the clever name
selection of search buffers.

emacs/notmuch-hello.el

@@ -45,11 +45,6 @@
 (defvar notmuch-hello-indent 4
   "How much to indent non-headers.")
 
-(defcustom notmuch-saved-searches nil
-  "A list of saved searches to display."
-  :type '(alist :key-type string :value-type string)
-  :group 'notmuch)
-
 (defcustom notmuch-show-logo t
   "Should the notmuch logo be shown?"
   :type 'boolean
@@ -207,14 +202,10 @@ diagonal."
 (defun notmuch-hello (&optional no-display)
   (interactive)
 
-  ;; Provide support for the deprecated name of this variable
+  ; Jump through a hoop to get this value from the deprecated variable
+  ; name (`notmuch-folders') or from the default value.
   (if (not notmuch-saved-searches)
-      (setq notmuch-saved-searches notmuch-folders))
-
-  ;; And set a default if neither has been set by the user
-  (if (not notmuch-saved-searches)
-      (setq notmuch-saved-searches '(("inbox" . "tag:inbox")
-				     ("unread" . "tag:unread"))))
+    (setq notmuch-saved-searches (notmuch-saved-searches)))
 
   (if no-display
       (set-buffer "*notmuch-hello*")

emacs/notmuch-lib.el

@@ -40,6 +40,24 @@
 
 ;;
 
+(defcustom notmuch-saved-searches nil
+  "A list of saved searches to display."
+  :type '(alist :key-type string :value-type string)
+  :group 'notmuch)
+
+(defun notmuch-saved-searches ()
+  "Common function for querying the notmuch-saved-searches variable.
+
+We do this as a function to support the old name of the
+variable (`notmuch-folders') as well as for the default value if
+the user hasn't set this variable with the old or new value."
+  (if notmuch-saved-searches
+      notmuch-saved-searches
+    (if notmuch-folders
+	notmuch-folders
+      '(("inbox" . "tag:inbox")
+	("unread" . "tag:unread")))))
+
 (defun notmuch-version ()
   "Return a string with the notmuch version number."
   (let ((long-string

emacs/notmuch.el

@@ -665,7 +665,7 @@ characters as well as `_.+-'.
   (let* ((folder (rassoc-if (lambda (key)
 			      (string-match (concat "^" (regexp-quote key))
 					    query))
-			    notmuch-folders))
+			    (notmuch-saved-searches)))
 	 (folder-name (car folder))
 	 (folder-query (cdr folder)))
     (cond ((and folder (equal folder-query query))