(internal-facep): Length is now 10.

(make-face, x-create-frame-with-faces): Make a face 10 elements long.
(internal-set-face-1): Don't call set-face-attribute-internal
if NAME is nil.
(set-face-font): Set the auto-flag to t or nil.
(face-spec-set): Clear out the font at the start,
if it was set automatically before.
(face-font-explicit): New function.
(set-face-font-auto): New function.
(set-face-font-explicit): New function.
(copy-face): Copy the face-font-external flag.
(internal-try-face-font): Use set-face-font-auto.

1 files changed, 41 insertions, 8 deletions

diff --git a/lisp/faces.el b/lisp/faces.el
index 09a8082bc3f..60690b648ed 100644
--- a/lisp/faces.el
+++ b/lisp/faces.el
@@ -31,11 +31,13 @@
  (put 'face-name 'byte-optimizer nil)
  (put 'face-id 'byte-optimizer nil)
  (put 'face-font 'byte-optimizer nil)
+ (put 'face-font-explicit 'byte-optimizer nil)
  (put 'face-foreground 'byte-optimizer nil)
  (put 'face-background 'byte-optimizer nil)
  (put 'face-stipple 'byte-optimizer nil)
  (put 'face-underline-p 'byte-optimizer nil)
  (put 'set-face-font 'byte-optimizer nil)
+ (put 'set-face-font-auto 'byte-optimizer nil)
  (put 'set-face-foreground 'byte-optimizer nil)
  (put 'set-face-background 'byte-optimizer nil)
  (put 'set-face-stipple 'byte-optimizer nil)
@@ -48,7 +50,7 @@
 
 ;;; Type checkers.
 (defsubst internal-facep (x)
-  (and (vectorp x) (= (length x) 9) (eq (aref x 0) 'face)))
+  (and (vectorp x) (= (length x) 10) (eq (aref x 0) 'face)))
 
 (defun facep (x)
   "Return t if X is a face name or an internal face vector."
@@ -78,6 +80,10 @@ If FRAME is t, report on the defaults for face FACE (for new frames).
 If FRAME is omitted or nil, use the selected frame."
   (aref (internal-get-face face frame) 3))
 
+(defun face-font-explicit (face &optional frame)
+  "Return non-nil if this face's font was explicitly specified."
+  (aref (internal-get-face face frame) 9))
+
 (defun face-foreground (face &optional frame)
   "Return the foreground color name of face FACE, or nil if unspecified.
 If the optional argument FRAME is given, report on face FACE in that frame.
@@ -153,8 +159,29 @@ in that frame; otherwise change each frame."
   (if (stringp font)
       (setq font (or (query-fontset font)
                      (x-resolve-font-name font 'default frame))))
+  (internal-set-face-1 face 'font font 3 frame)
+  ;; Record that this face's font was set explicitly, not automatically,
+  ;; unless we are setting it to nil.
+  (internal-set-face-1 face nil (not (null font)) 9 frame))
+
+(defun set-face-font-auto (face font &optional frame)
+  "Change the font of face FACE to FONT (a string), for an automatic change.
+An automatic change means that we don't change the \"explicit\" flag;
+if the font was derived from the frame font before, it is now.
+If the optional FRAME argument is provided, change only
+in that frame; otherwise change each frame."
+  (interactive (internal-face-interactive "font"))
+  (if (stringp font)
+      (setq font (or (query-fontset font)
+                     (x-resolve-font-name font 'default frame))))
   (internal-set-face-1 face 'font font 3 frame))
 
+(defun set-face-font-explicit (face flag &optional frame)
+  "Set the explicit-font flag of face FACE to FLAG.
+If the optional FRAME argument is provided, change only
+in that frame; otherwise change each frame."
+  (internal-set-face-1 face 'font flag 9 frame))
+
 (defun set-face-foreground (face color &optional frame)
   "Change the foreground color of face FACE to COLOR (a string).
 If the optional FRAME argument is provided, change only
@@ -403,9 +430,9 @@ If NAME is already a face, it is simply returned."
             (if (eq name 'inverse-video)
                 (or (eq value (aref internal-face index))
                     (invert-face face frame))
-              (if (fboundp 'set-face-attribute-internal)
-                  (set-face-attribute-internal (face-id face)
-                                               name value frame))))
+              (and name (fboundp 'set-face-attribute-internal)
+                   (set-face-attribute-internal (face-id face)
+                                                name value frame))))
         (aset internal-face index value)))))
 
 
@@ -470,7 +497,7 @@ and always make a face whose attributes are all nil.
 If the face already exists, it is unmodified."
   (interactive "SMake face: ")
   (or (internal-find-face name)
-      (let ((face (make-vector 9 nil)))
+      (let ((face (make-vector 10 nil)))
         (aset face 0 'face)
         (aset face 1 name)
         (let* ((frames (frame-list))
@@ -611,6 +638,8 @@ to NEW-FACE on frame NEW-FRAME."
           (set-face-font new-face (face-font old-face frame) new-frame)
         (error
          (set-face-font new-face nil new-frame)))
+      (set-face-font-explicit new-face (face-font-explicit old-face frame)
+                              new-frame)
       (set-face-foreground new-face (face-foreground old-face frame) new-frame)
       (set-face-background new-face (face-background old-face frame) new-frame)
       (set-face-stipple new-face
@@ -700,7 +729,7 @@ set its foreground and background to the default background and foreground."
 (defun internal-try-face-font (face font &optional frame)
   "Like set-face-font, but returns nil on failure instead of an error."
   (condition-case ()
-      (set-face-font face font frame)
+      (set-face-font-auto face font frame)
     (error nil)))
 
 ;; Manipulating font names.
@@ -1126,6 +1155,10 @@ See `defface' for information about SPEC."
              (display (nth 0 entry))
              (attrs (nth 1 entry)))
         (setq tail (cdr tail))
+        ;; If the font was set automatically, clear it out
+        ;; to allow it to be set it again.
+        (unless (face-font-explicit face frame)
+          (set-face-font face nil frame))
         (modify-face face nil nil nil nil nil nil frame)
         (when (face-spec-set-match-display display frame)
           (face-spec-set-1 face frame attrs ':foreground 'set-face-foreground)
@@ -1219,7 +1252,7 @@ If FRAME is nil, the current FRAME is used."
                                      (vector 'face
                                              (face-name (cdr elt))
                                              (face-id (cdr elt))
-                                             nil nil nil nil nil nil)))
+                                             nil nil nil nil nil nil nil)))
                             global-face-data))
               (set-frame-face-alist frame faces)
 
@@ -1274,7 +1307,7 @@ If FRAME is nil, the current FRAME is used."
                        (get face 'face-defface-spec)))
              (global (cdr (assq face global-face-data)))
              (local (cdr (car rest))))
-        (when spec 
+        (when spec
           (face-spec-set face spec frame))
         (face-fill-in face global frame)
         (make-face-x-resource-internal local frame))