lisp/frameset.el: Allow orphaned minibufferless frames.

(frameset-filter-minibuffer): Deal with the case that the minibuffer
parameter was already set in FILTERED.  Doc fix.
(frameset--record-minibuffer-relationships): Allow saving a
minibufferless frame without its corresponding minibuffer frame.
(frameset--reuse-frame): Accept a match from an orphaned minibufferless
frame, if the frame id matches.
(frameset--minibufferless-last-p): Sort non-orphaned minibufferless
frames before orphaned ones.
(frameset-restore): Warn about orphaned windows, instead of error out.

2 files changed, 58 insertions, 32 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index b83a752f2eb..4b9ea280f98 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -2,6 +2,15 @@
 
         * frameset.el (frameset--prop-setter): New function.
         (frameset-prop): Add gv-setter declaration.
+        (frameset-filter-minibuffer): Deal with the case that the minibuffer
+        parameter was already set in FILTERED.  Doc fix.
+        (frameset--record-minibuffer-relationships): Allow saving a
+        minibufferless frame without its corresponding minibuffer frame.
+        (frameset--reuse-frame): Accept a match from an orphaned minibufferless
+        frame, if the frame id matches.
+        (frameset--minibufferless-last-p): Sort non-orphaned minibufferless
+        frames before orphaned ones.
+        (frameset-restore): Warn about orphaned windows, instead of error out.
 
 2013-08-14  Martin Rudalics  <rudalics@gmx.at>
 
diff --git a/lisp/frameset.el b/lisp/frameset.el
index 74432db892c..7cdab7e3fcc 100644
--- a/lisp/frameset.el
+++ b/lisp/frameset.el
@@ -570,15 +570,22 @@ see `frameset-filter-alist'."
       (not (stringp (cdr current)))
       (not (string-match-p "^unspecified-[fb]g$" (cdr current)))))
 
-(defun frameset-filter-minibuffer (current _filtered _parameters saving)
-  "When saving, convert (minibuffer . #<window>) to (minibuffer . t).
+(defun frameset-filter-minibuffer (current filtered _parameters saving)
+  "Force the minibuffer parameter to have a sensible value.
+
+When saving, convert (minibuffer . #<window>) to (minibuffer . t).
+When restoring, if there are two copies, keep the one pointing to
+a live window.
 
 For the meaning of CURRENT, FILTERED, PARAMETERS and SAVING,
 see `frameset-filter-alist'."
-  (or (not saving)
-      (if (windowp (cdr current))
-          '(minibuffer . t)
-        t)))
+  (let ((value (cdr current)) mini)
+    (cond (saving
+           (if (windowp value) '(minibuffer . t) t))
+          ((setq mini (assq 'minibuffer filtered))
+           (when (windowp value) (setcdr mini value))
+           nil)
+          (t t))))
 
 (defun frameset-filter-shelve-param (current _filtered parameters saving
                                              &optional prefix)
@@ -721,16 +728,18 @@ FRAME-LIST is a list of frames.  Internal use only."
   (dolist (frame frame-list)
     (unless (frame-parameter frame 'frameset--mini)
       (frameset--set-id frame)
-      (let* ((mb-frame (window-frame (minibuffer-window frame)))
-             (id (and mb-frame (frameset-frame-id mb-frame))))
-        (if (null id)
-            (error "Minibuffer frame %S for %S is not being saved" mb-frame frame)
-          ;; For minibufferless frames, frameset--mini is a cons
-          ;; (nil . FRAME-ID), where FRAME-ID is the frameset--id
-          ;; of the frame containing its minibuffer window.
-          (set-frame-parameter frame
-                               'frameset--mini
-                               (cons nil id)))))))
+      (let ((mb-frame (window-frame (minibuffer-window frame))))
+        ;; For minibufferless frames, frameset--mini is a cons
+        ;; (nil . FRAME-ID), where FRAME-ID is the frameset--id of
+        ;; the frame containing its minibuffer window.
+        ;; FRAME-ID can be set to nil, if FRAME-LIST doesn't contain
+        ;; the minibuffer frame of a minibufferless frame; we allow
+        ;; it without trying to second-guess the user.
+        (set-frame-parameter frame
+                             'frameset--mini
+                             (cons nil
+                                   (and mb-frame
+                                        (frameset-frame-id mb-frame))))))))
 
 ;;;###autoload
 (cl-defun frameset-save (frame-list
@@ -909,10 +918,12 @@ is the parameter alist of the frame being restored.  Internal use only."
            (setq frame (frameset--find-frame-if
                         (lambda (f id mini-id)
                           (and (frameset-frame-id-equal-p f id)
-                               (frameset-frame-id-equal-p (window-frame
-                                                           (minibuffer-window f))
-                                                          mini-id)))
-                        display (cdr (assq 'frameset--id parameters)) (cdr mini))))
+                               (or (null mini-id) ; minibuffer frame not saved
+                                   (frameset-frame-id-equal-p
+                                    (window-frame (minibuffer-window f))
+                                    mini-id))))
+                        display
+                        (cdr (assq 'frameset--id parameters)) (cdr mini))))
           (t
            ;; Default to just finding a frame in the same display.
            (setq frame (frameset--find-frame-if nil display))))
@@ -1007,7 +1018,7 @@ Internal use only."
     (cond ((eq id-def1 t) t)
           ((eq id-def2 t) nil)
           ((not (eq hasmini1 hasmini2)) (eq hasmini1 t))
-          ((eq hasmini1 nil) (string< id-def1 id-def2))
+          ((eq hasmini1 nil) (or id-def1 id-def2))
           (t t))))
 
 (defun frameset-keep-original-display-p (force-display)
@@ -1098,7 +1109,7 @@ All keyword parameters default to nil."
           (condition-case-unless-debug err
               (let* ((d-mini (cdr (assq 'frameset--mini frame-cfg)))
                      (mb-id (cdr d-mini))
-                     (default (and (booleanp mb-id) mb-id))
+                     (default (and (car d-mini) mb-id))
                      (force-display (if (functionp force-display)
                                         (funcall force-display frame-cfg window-cfg)
                                       force-display))
@@ -1142,16 +1153,22 @@ All keyword parameters default to nil."
                       (setq frame-cfg (append '((tool-bar-lines . 0) (menu-bar-lines . 0))
                                               frame-cfg))))
                    (t ;; Frame depends on other frame's minibuffer window.
-                    (let* ((mb-frame (or (frameset-frame-with-id mb-id)
-                                         (error "Minibuffer frame %S not found" mb-id)))
-                           (mb-param (assq 'minibuffer frame-cfg))
-                           (mb-window (minibuffer-window mb-frame)))
-                      (unless (and (window-live-p mb-window)
-                                   (window-minibuffer-p mb-window))
-                        (error "Not a minibuffer window %s" mb-window))
-                      (if mb-param
-                          (setcdr mb-param mb-window)
-                        (push (cons 'minibuffer mb-window) frame-cfg)))))
+                    (when mb-id
+                      (let ((mb-frame (frameset-frame-with-id mb-id))
+                            (mb-window nil))
+                        (if (not mb-frame)
+                            (delay-warning 'frameset
+                                           (format "Minibuffer frame %S not found" mb-id)
+                                           :warning)
+                          (setq mb-window (minibuffer-window mb-frame))
+                          (unless (and (window-live-p mb-window)
+                                       (window-minibuffer-p mb-window))
+                            (delay-warning 'frameset
+                                           (format "Not a minibuffer window %s" mb-window)
+                                           :warning)
+                            (setq mb-window nil)))
+                        (when mb-window
+                          (push (cons 'minibuffer mb-window) frame-cfg))))))
                   ;; OK, we're ready at last to create (or reuse) a frame and
                   ;; restore the window config.
                   (setq frame (frameset--restore-frame frame-cfg window-cfg