(read-feature): Reimplement. New optional arg LOADED-P.

(unload-feature): Update interactive spec accordingly.

1 files changed, 15 insertions, 12 deletions

diff --git a/lisp/loadhist.el b/lisp/loadhist.el
index 39d51a280f5..35b010074d0 100644
--- a/lisp/loadhist.el
+++ b/lisp/loadhist.el
@@ -111,17 +111,18 @@ A library name is equivalent to the file name that `load-library' would load."
           (setq dependents (cons (car x) dependents))))
     dependents))
 
-(defun read-feature (prompt)
-  "Read a feature name \(string\) from the minibuffer.
-Prompt with PROMPT and completing from `features', and
-return the feature \(symbol\)."
-  (intern (completing-read prompt
-                           (mapcar (lambda (feature)
-                                     (list (symbol-name feature)))
-                                   features)
-                           ;; Complete only features loaded from a file
-                           #'(lambda (f) (feature-file (intern (car f))))
-                           t)))
+(defun read-feature (prompt &optional loaded-p)
+  "Read feature name from the minibuffer, prompting with string PROMPT.
+If optional second arg LOADED-P is non-nil, the feature must be loaded
+from a file."
+  (intern
+   (completing-read prompt
+                    (cons nil features)
+                    (and loaded-p
+                         #'(lambda (f)
+                             (and f     ; ignore nil
+                                  (feature-file f))))
+                    loaded-p)))
 
 (defvaralias 'loadhist-hook-functions 'unload-feature-special-hooks)
 (defvar unload-feature-special-hooks
@@ -162,7 +163,9 @@ the package's feature list (before anything is unbound) in the
 variable `unload-hook-features-list' and could remove features from it
 in the event that the package has done something normally-ill-advised,
 such as redefining an Emacs function."
-  (interactive (list (read-feature "Feature: ") current-prefix-arg))
+  (interactive
+   (list
+    (read-feature "Unload feature: " t) current-prefix-arg))
   (unless (featurep feature)
     (error "%s is not a currently loaded feature" (symbol-name feature)))
   (unless force