* etc/NEWS: Move entry since it's an incompatible change.
* lisp/emacs-lisp/shortdoc.el (vector): Make the example relevant.
* lisp/subr.el (copy-tree): Rename second argument,
since 'vector-like' is a term with a specific meaning in Emacs
but not the one intended here.
* doc/lispref/lists.texi (Building Lists): Rename second argument,
and make it clear that the input must be acyclic.
* doc/lispref/records.texi (Record Functions):
Be more precise: `copy-sequence` is used to copy records,
`copy-tree` copies trees made of records etc.
* test/lisp/subr-tests.el (subr--copy-tree): Extend and strengthen the
test considerably, using the print-circle trick to detect structure
sharing precisely.

* doc/lispref/lists.texi (Building Cons Cells and Lists): Document
new behavior of 'copy-tree'.
* doc/lispref/records.texi (Record Functions): Cross-reference to
lists.texi.
* etc/NEWS: Mention change.  (Bug#63509)
* lisp/emacs-lisp/shortdoc.el: Add 'copy-tree' example to vector
group.
* lisp/subr.el (copy-tree): Recurse into records as well as
vectors when optional second argument is non-nil. Rename second
argument from VECP to VECTOR-LIKE-P.
* test/lisp/subr-tests.el: Test new behavior.

* doc/lispref/lists.texi (Rearrangement): Explicitly say that dotted
lists are valid args to `nconc` and give an example.

There is no particular requirement for safe-copy-tree so let's make it
internal for now.  The new implementation is faster and more correct.

* doc/lispref/lists.texi (Building Lists):
* etc/NEWS:  Remove doc and announcement.
* lisp/subr.el (safe-copy-tree--seen, safe-copy-tree--1)
(safe-copy-tree): Remove old version.
* lisp/emacs-lisp/bytecomp.el (bytecomp--copy-tree-seen)
(bytecomp--copy-tree-1, bytecomp--copy-tree): Add new version.
(byte-compile-initial-macro-environment): Use it.
* test/lisp/subr-tests.el (subr--safe-copy-tree):
* test/lisp/emacs-lisp/bytecomp-tests.el (bytecomp--copy-tree):
Move and improve tests.

* lisp/emacs-lisp/bytecomp.el (compile-defun): Remove unintended change.

* lisp/subr.el (safe-copy-tree--seen): Correct grammatical error in doc
string.
(safe-copy-tree): Delete hash table at end of function.

* doc/lispref/lists.texi (Building Lists): Add an "@end defun" line.

This fixes bug #61962.

* lisp/subr.el (safe-copy-tree): New function.

* lisp/emacs-lisp/bytecomp.el (byte-compile-initial-macro-environment): Amend
the entry for eval-and-compile to use safe-copy-tree and
byte-run-strip-symbol-positions for the eval part.

* doc/lispref/lists.texi (Building Lists): Document safe-copy-tree.

* etc/NEWS: Note the new function safe-copy-tree.

* doc/lispref/lists.texi (Cons Cells): Add cross-reference
to 'proper-list-p' documentation.

* doc/lispref/lists.texi (Property Lists): Document 'plistp'.
(Bug#61293)

* doc/lispref/lists.texi (Plist Access): Improve description of
default predicate.
* lisp/emacs-lisp/cl-extra.el (cl-getf, cl--set-getf): Assume
plist-member always returns a cons.
* lisp/emacs-lisp/gv.el (plist-get): Support new optional predicate
argument (bug#47425#91).
* lisp/emacs-lisp/map.el: Bump minor version.
(map--dispatch): Remove now that bug#58563 is fixed.  Break two
remaining uses out into corresponding cl-defmethods.
(map--plist-p): Add docstring.
(map--plist-has-predicate, map--plist-member-1, map--plist-member)
(map--plist-put-1, map--plist-put): New definitions for supporting
predicate argument backward compatibly.
(map-elt): Fix generalized variable getter under a
predicate (bug#58531).  Use predicate when given a plist.
(map-put): Avoid gratuitous warnings when called without the hidden
predicate argument.  Improve obsoletion message.
(map-put!): Use predicate when given a plist.
(map-contains-key): Ditto.  Declare forgotten
advertised-calling-convention (bug#58531#19).
(map--put): Group definition in file together with that of map-put!.
* lisp/files-x.el (connection-local-normalize-criteria): Simplify
using mapcan + plist-get.
* lisp/net/eudc.el (eudc--plist-member): New convenience function.
(eudc-plist-member, eudc-plist-get, eudc-lax-plist-get): Use it
instead of open-coding plist-member.
* src/fns.c (Fplist_get, plist_get, Fplist_put, plist_put): Pass the
plist element as the first argument to the predicate, for
consistency with assoc + alist-get.
(Fplist_member, plist_member): Move from widget to plist section.
Open-code the EQ case in plist_member, and call it from
Fplist_member in that case, rather than the other way around.

* test/lisp/apropos-tests.el (apropos-tests-format-plist): Avoid
polluting obarray.
* test/lisp/emacs-lisp/cl-extra-tests.el (cl-getf): Extend test with
generalized variables, degenerate plists, and improper lists.
* test/lisp/emacs-lisp/gv-tests.el: Byte-compile file; in the
meantime bug#24402 seems to have been fixed or worked around.
(gv-setter-edebug): Inhibit printing messages.
(gv-plist-get): Avoid modifying constant literals.  Also test with a
predicate argument.
* test/lisp/emacs-lisp/map-tests.el (with-maps-do): Simplify
docstring.
(test-map-elt-testfn): Rename...
(test-map-elt-testfn-alist): ...to this.  Also test with a predicate
argument.
(test-map-elt-testfn-plist, test-map-elt-gv, test-map-elt-signature)
(test-map-put!-plist, test-map-put!-signature)
(test-map-contains-key-signature, test-map-plist-member)
(test-map-plist-put): New tests.
(test-map-contains-key-testfn): Also test with a predicate argument.
(test-map-setf-alist-overwrite-key, test-map-setf-plist-insert-key)
(test-map-setf-plist-overwrite-key): Avoid modifying constant
literals.
(test-hash-table-setf-insert-key)
(test-hash-table-setf-overwrite-key): Fix indentation.
(test-setf-map-with-function): Make test more precise.
* test/lisp/net/eudc-tests.el: New file.
* test/lisp/subr-tests.el (test-plistp): Extend test with circular
list.
* test/src/fns-tests.el (test-cycle-equal, test-cycle-nconc): Move
from plist section to circular list section.
(plist-put/odd-number-of-elements): Avoid modifying constant
literals.
(plist-member/improper-list): Simplify.
(test-plist): Move to plist section.  Also test with a predicate
argument.