Revamp face-spec-set to be more analogous to setq for faces.

* lisp/faces.el (face-spec-set): Change the third arg to specify
whether this function is being called via defface, customize, or a
third party.  Set the appropriate symbol properties.  Clear the
override spec if setting via Custom.  Initialize face if necessary.
(face-spec-recalc): Allow theme faces to completely replace the
defface spec, in the same way as custom faces (Bug#8454).

* lisp/cus-edit.el (custom-face-set, custom-face-mark-to-save)
(custom-face-reset-saved, custom-face-mark-to-reset-standard):
Simplify by using the new arg to face-spec-set.

* lisp/cus-face.el (custom-declare-face): Move face initialization to
face-spec-set.
(custom-theme-set-faces): Don't initialize the face name here, as
that is now done in face-spec-set.

* lisp/emacs-lisp/lisp-mode.el (eval-defun-1): When evaluating defface,
reset face-override-spec too, and use custom-declare-face.

Fixes: debbugs:4988

1 files changed, 67 insertions, 32 deletions

diff --git a/lisp/faces.el b/lisp/faces.el
index 928174c3954..2a0b77b19c4 100644
--- a/lisp/faces.el
+++ b/lisp/faces.el
@@ -1587,44 +1587,79 @@ If SPEC is nil, return nil."
 		  (mapcar (lambda (x) (list (car x) 'unspecified))
 			  face-attribute-name-alist)))))
 
-(defun face-spec-set (face spec &optional for-defface)
-  "Set and apply the face spec for FACE.
-If the optional argument FOR-DEFFACE is omitted or nil, set the
-overriding spec to SPEC, recording it in the `face-override-spec'
-property of FACE.  See `defface' for the format of SPEC.
-
-If FOR-DEFFACE is non-nil, set the base spec (the one set by
-`defface' and Custom).  In this case, SPEC is ignored; the caller
-is responsible for putting the face spec in the `saved-face',
-`customized-face', or `face-defface-spec', as appropriate.
-
-The appearance of FACE is controlled by the base spec, by any
-custom theme specs on top of that, and by the overriding spec on
-top of all the rest."
-  (if for-defface
-      ;; When we reset the face based on its custom spec, then it is
-      ;; unmodified as far as Custom is concerned.
-      (put (or (get face 'face-alias) face) 'face-modified nil)
-    ;; When we change a face based on a spec from outside custom,
-    ;; record it for future frames.
-    (put (or (get face 'face-alias) face) 'face-override-spec spec))
-  ;; Reset each frame according to the rules implied by all its specs.
-  (dolist (frame (frame-list))
-    (face-spec-recalc face frame)))
+(defun face-spec-set (face spec &optional spec-type)
+  "Set the face spec SPEC for FACE.
+See `defface' for the format of SPEC.
+
+The appearance of each face is controlled by its spec, and by the
+internal face attributes (which can be frame-specific and can be
+set via `set-face-attribute').
+
+The argument SPEC-TYPE determines which spec to set:
+  nil or `face-override-spec' means the override spec (which is
+    usually what you want if calling this function outside of
+    Custom code);
+  `customized-face' or `saved-face' means the customized spec or
+    the saved custom spec;
+  `face-defface-spec' means the default spec
+    (usually set only via `defface');
+  `reset' means to ignore SPEC, but clear the `customized-face'
+    and `face-override-spec' specs;
+Any other value means not to set any spec, but to run the
+function for its other effects.
+
+In addition to setting the face spec, this function defines FACE
+as a valid face name if it is not already one, and (re)calculates
+the face's attributes on existing frames."
+  (if (get face 'face-alias)
+      (setq face (get face 'face-alias)))
+  ;; Save SPEC to the relevant symbol property.
+  (unless spec-type
+    (setq spec-type 'face-override-spec))
+  (if (memq spec-type '(face-defface-spec face-override-spec
+			customized-face saved-face))
+      (put face spec-type spec))
+  (if (memq spec-type '(reset saved-face))
+      (put face 'customized-face nil))
+  ;; Setting the face spec via Custom empties out any override spec,
+  ;; similar to how setting a variable via Custom changes its valus.
+  (if (memq spec-type '(customized-face saved-face reset))
+      (put face 'face-override-spec nil))
+  ;; If we reset the face based on its custom spec, it is unmodified
+  ;; as far as Custom is concerned.
+  (unless (eq face 'face-override-spec)
+    (put face 'face-modified nil))
+  (if (facep face)
+      ;; If the face already exists, recalculate it.
+      (dolist (frame (frame-list))
+	(face-spec-recalc face frame))
+    ;; Otherwise, initialize it on all frames.
+    (make-empty-face face)
+    (let ((value (face-user-default-spec face))
+	  (have-window-system (memq initial-window-system '(x w32 ns))))
+      (dolist (frame (frame-list))
+	(face-spec-set-2 face frame value)
+ 	(when (memq (window-system frame) '(x w32 ns))
+ 	  (setq have-window-system t)))
+      (if have-window-system
+ 	  (make-face-x-resource-internal face)))))
 
 (defun face-spec-recalc (face frame)
   "Reset the face attributes of FACE on FRAME according to its specs.
 This applies the defface/custom spec first, then the custom theme specs,
 then the override spec."
+  (while (get face 'face-alias)
+    (setq face (get face 'face-alias)))
   (face-spec-reset-face face frame)
-  (let ((face-sym (or (get face 'face-alias) face)))
-    (or (get face 'customized-face)
-	(get face 'saved-face)
-	(face-spec-set-2 face frame (face-default-spec face)))
-    (let ((theme-faces (reverse (get face-sym 'theme-face))))
-      (dolist (spec theme-faces)
-	(face-spec-set-2 face frame (cadr spec))))
-    (face-spec-set-2 face frame (get face-sym 'face-override-spec))))
+  ;; If FACE is customized or themed, set the custom spec from
+  ;; `theme-face' records, which completely replace the defface spec
+  ;; rather than inheriting from it.
+  (let ((theme-faces (get face 'theme-face)))
+    (if theme-faces
+	(dolist (spec (reverse theme-faces))
+	  (face-spec-set-2 face frame (cadr spec)))
+      (face-spec-set-2 face frame (face-default-spec face))))
+  (face-spec-set-2 face frame (get face 'face-override-spec)))
 
 (defun face-spec-set-2 (face frame spec)
   "Set the face attributes of FACE on FRAME according to SPEC."