Reduce face-related consing during frame creation.

* faces.el (face--attributes-unspecified): Compute the "unspecified"
attribute list once.
(face-spec-reset-face): Use it instead of building the list.

1 files changed, 8 insertions, 3 deletions

diff --git a/lisp/faces.el b/lisp/faces.el
index 4e7f1a42bff..de8a0b5bcb1 100644
--- a/lisp/faces.el
+++ b/lisp/faces.el
@@ -1598,6 +1598,13 @@ is given, in which case return its value instead."
           result
         no-match-retval))))
 
+;; When over 80 faces get processed at frame creation time, all but
+;; one specifying all attributes as "unspecified", generating this
+;; list every time means a lot of consing.
+(defconst face--attributes-unspecified
+  (apply 'append
+         (mapcar (lambda (x) (list (car x) 'unspecified))
+                 face-attribute-name-alist)))
 
 (defun face-spec-reset-face (face &optional frame)
   "Reset all attributes of FACE on FRAME to unspecified."
@@ -1622,9 +1629,7 @@ is given, in which case return its value instead."
                                      "unspecified-fg"
                                    "unspecified-bg")))))
            ;; For all other faces, unspecify all attributes.
-           (apply 'append
-                  (mapcar (lambda (x) (list (car x) 'unspecified))
-                          face-attribute-name-alist)))))
+           face--attributes-unspecified)))
 
 (defun face-spec-set (face spec &optional spec-type)
   "Set the face spec SPEC for FACE.