Minor custom.el simplifications

* lisp/custom.el (custom-quote): Duplicate macroexp-quote.
(custom-load-symbol, customize-mark-to-save, customize-mark-as-set)
(custom-theme-name-valid-p, enable-theme, custom-enabled-themes)
(disable-theme): Simplify logic.

1 files changed, 46 insertions, 57 deletions

diff --git a/lisp/custom.el b/lisp/custom.el
index 1c667c8aa2d..a08f7fda705 100644
--- a/lisp/custom.el
+++ b/lisp/custom.el
@@ -630,14 +630,12 @@ The result is that the change is treated as having been made through Custom."
     (let ((custom-load-recursion t))
       ;; Load these files if not already done,
       ;; to make sure we know all the dependencies of SYMBOL.
-      (condition-case nil
-          (require 'cus-load)
-        (error nil))
-      (condition-case nil
-          (require 'cus-start)
-        (error nil))
+      (ignore-errors
+        (require 'cus-load))
+      (ignore-errors
+        (require 'cus-start))
       (dolist (load (get symbol 'custom-loads))
-        (cond ((symbolp load) (condition-case nil (require load) (error nil)))
+        (cond ((symbolp load) (ignore-errors (require load)))
               ;; This is subsumed by the test below, but it's much faster.
               ((assoc load load-history))
               ;; This was just (assoc (locate-library load) load-history)
@@ -655,7 +653,7 @@ The result is that the change is treated as having been made through Custom."
               ;; We are still loading it when we call this,
               ;; and it is not in load-history yet.
               ((equal load "cus-edit"))
-              (t (condition-case nil (load load) (error nil))))))))
+              (t (ignore-errors (load load))))))))
 
 (defvar custom-local-buffer nil
   "Non-nil, in a Customization buffer, means customize a specific buffer.
@@ -688,16 +686,12 @@ this sets the local binding in that buffer instead."
 
 (defun custom-quote (sexp)
   "Quote SEXP if it is not self quoting."
-  (if (or (memq sexp '(t nil))
-          (keywordp sexp)
-          (and (listp sexp)
-               (memq (car sexp) '(lambda)))
-          (stringp sexp)
-          (numberp sexp)
-          (vectorp sexp)
-;;;       (and (fboundp 'characterp)
-;;;            (characterp sexp))
-          )
+  ;; Can't use `macroexp-quote' because it is loaded after `custom.el'
+  ;; during bootstrap.  See `loadup.el'.
+  (if (and (not (consp sexp))
+           (or (keywordp sexp)
+               (not (symbolp sexp))
+               (booleanp sexp)))
       sexp
     (list 'quote sexp)))
 
@@ -718,12 +712,10 @@ Return non-nil if the `saved-value' property actually changed."
          (standard (get symbol 'standard-value))
          (comment (get symbol 'customized-variable-comment)))
     ;; Save default value if different from standard value.
-    (if (or (null standard)
-            (not (equal value (condition-case nil
-                                  (eval (car standard))
-                                (error nil)))))
-        (put symbol 'saved-value (list (custom-quote value)))
-      (put symbol 'saved-value nil))
+    (put symbol 'saved-value
+         (unless (and standard
+                      (equal value (ignore-errors (eval (car standard)))))
+           (list (custom-quote value))))
     ;; Clear customized information (set, but not saved).
     (put symbol 'customized-value nil)
     ;; Save any comment that might have been set.
@@ -747,9 +739,8 @@ Return non-nil if the `customized-value' property actually changed."
          (old (or (get symbol 'saved-value) (get symbol 'standard-value))))
     ;; Mark default value as set if different from old value.
     (if (not (and old
-                  (equal value (condition-case nil
-                                   (eval (car old))
-                                 (error nil)))))
+                  (equal value (ignore-errors
+                                 (eval (car old))))))
         (progn (put symbol 'customized-value (list (custom-quote value)))
                (custom-push-theme 'theme-value symbol 'user 'set
                                   (custom-quote value)))
@@ -1296,11 +1287,9 @@ query also about adding HASH to `custom-safe-themes'."
 (defun custom-theme-name-valid-p (name)
   "Return t if NAME is a valid name for a Custom theme, nil otherwise.
 NAME should be a symbol."
-  (and (symbolp name)
-       name
-       (not (or (zerop (length (symbol-name name)))
-                (eq name 'user)
-                (eq name 'changed)))))
+  (and (not (memq name '(nil user changed)))
+       (symbolp name)
+       (not (string= "" (symbol-name name)))))
 
 (defun custom-available-themes ()
   "Return a list of Custom themes available for loading.
@@ -1356,8 +1345,8 @@ function runs.  To disable other themes, use `disable-theme'."
                       (completing-read
                        "Enable custom theme: "
                        obarray (lambda (sym) (get sym 'theme-settings)) t))))
-  (if (not (custom-theme-p theme))
-      (error "Undefined Custom theme %s" theme))
+  (unless (custom-theme-p theme)
+    (error "Undefined Custom theme %s" theme))
   (let ((settings (get theme 'theme-settings)))
     ;; Loop through theme settings, recalculating vars/faces.
     (dolist (s settings)
@@ -1397,18 +1386,18 @@ Setting this variable through Customize calls `enable-theme' or
          (let (failures)
            (setq themes (delq 'user (delete-dups themes)))
            ;; Disable all themes not in THEMES.
-           (if (boundp symbol)
-               (dolist (theme (symbol-value symbol))
-                 (if (not (memq theme themes))
-                     (disable-theme theme))))
+           (dolist (theme (and (boundp symbol)
+                               (symbol-value symbol)))
+             (unless (memq theme themes)
+               (disable-theme theme)))
            ;; Call `enable-theme' or `load-theme' on each of THEMES.
            (dolist (theme (reverse themes))
              (condition-case nil
                  (if (custom-theme-p theme)
                      (enable-theme theme)
                    (load-theme theme))
-               (error (setq failures (cons theme failures)
-                            themes (delq theme themes)))))
+               (error (push theme failures)
+                      (setq themes (delq theme themes)))))
            (enable-theme 'user)
            (custom-set-default symbol themes)
            (when failures
@@ -1441,23 +1430,23 @@ See `custom-enabled-themes' for a list of enabled themes."
             ;; If the face spec specified by this theme is in the
             ;; saved-face property, reset that property.
             (when (equal (nth 3 s) (get symbol 'saved-face))
-              (put symbol 'saved-face (and val (cadr (car val)))))))))
-      ;; Recompute faces on all frames.
-      (dolist (frame (frame-list))
-        ;; We must reset the fg and bg color frame parameters, or
-        ;; `face-set-after-frame-default' will use the existing
-        ;; parameters, which could be from the disabled theme.
-        (set-frame-parameter frame 'background-color
-                             (custom--frame-color-default
-                              frame :background "background" "Background"
-                              "unspecified-bg" "white"))
-        (set-frame-parameter frame 'foreground-color
-                             (custom--frame-color-default
-                              frame :foreground "foreground" "Foreground"
-                              "unspecified-fg" "black"))
-        (face-set-after-frame-default frame))
-      (setq custom-enabled-themes
-            (delq theme custom-enabled-themes)))))
+              (put symbol 'saved-face (cadar val))))))))
+    ;; Recompute faces on all frames.
+    (dolist (frame (frame-list))
+      ;; We must reset the fg and bg color frame parameters, or
+      ;; `face-set-after-frame-default' will use the existing
+      ;; parameters, which could be from the disabled theme.
+      (set-frame-parameter frame 'background-color
+                           (custom--frame-color-default
+                            frame :background "background" "Background"
+                            "unspecified-bg" "white"))
+      (set-frame-parameter frame 'foreground-color
+                           (custom--frame-color-default
+                            frame :foreground "foreground" "Foreground"
+                            "unspecified-fg" "black"))
+      (face-set-after-frame-default frame))
+    (setq custom-enabled-themes
+          (delq theme custom-enabled-themes))))
 
 ;; Only used if window-system not null.
 (declare-function x-get-resource "frame.c"