master 1af91d2: Don't consider obsolete commands for completion in some cases

[Lars Ingebrigtsen]

branch: master
commit 1af91d271e077134e272055407fb8c4312a7579b
Author: Stefan Kangas <stefan@marxist.se>
Commit: Lars Ingebrigtsen <larsi@gnus.org>

    Don't consider obsolete commands for completion in some cases
    
    * lisp/simple.el (read-extended-command): Exclude obsolete commands
    that are either lacking a 'current-name' or were obsoleted in a
    previous major version (bug#43300).
    
    (There's been some back and forth here.  Obsolete commands used to be
    treated normally for completion, and then they were removed.  Then
    they were put back again, but annotated with what they were
    obsoleting.  There was some pushback on this change, so this latest
    changes is a compromise between the last two states.)
---
 etc/NEWS       |  5 +++--
 lisp/simple.el | 19 ++++++++++++++++++-
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/etc/NEWS b/etc/NEWS
index 205f43c..18831e0 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -389,9 +389,10 @@ setting the variable 'auto-save-visited-mode' 
buffer-locally to nil.
 description of the properties.  Likewise 'button-describe' does the
 same for a button.
 
-** Obsolete commands are no longer hidden from command completion.
+** Obsolete aliases are no longer hidden from command completion.
 Completion of command names now considers obsolete aliases as
-candidates.  Invoking a command via an obsolete alias now mentions the
+candidates, if they were marked obsolete in the current major version
+of Emacs.  Invoking a command via an obsolete alias now mentions the
 obsolescence fact and shows the new name of the command.
 
 +++
diff --git a/lisp/simple.el b/lisp/simple.el
index b4e34f1e..35bb472 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -2006,7 +2006,24 @@ This function uses the `read-extended-command-predicate' 
user option."
             '(metadata
               (affixation-function . read-extended-command--affixation)
               (category . command))
-           (complete-with-action action obarray string pred)))
+           (let ((pred
+                  (if (memq action '(nil t))
+                      ;; Exclude from completions obsolete commands
+                      ;; lacking a `current-name', or where `when' is
+                      ;; not the current major version.
+                      (lambda (sym)
+                        (let ((obsolete (get sym 'byte-obsolete-info)))
+                          (and (funcall pred sym)
+                               (or (equal string (symbol-name sym))
+                                   (not obsolete)
+                                   (and
+                                    ;; Has a current-name.
+                                    (functionp (car obsolete))
+                                    ;; when >= emacs-major-version
+                                    (>= (car (version-to-list (caddr 
obsolete)))
+                                        emacs-major-version))))))
+                    pred)))
+             (complete-with-action action obarray string pred))))
        (lambda (sym)
          (and (commandp sym)
               (cond ((null read-extended-command-predicate))