Problem reported by Paul Pogonyshev (Bug#31938).
* src/editfns.c: Include math.h, for trunc.
(styled_format): For %d, truncate floating-point numbers and
convert -0 to 0, going back to how Emacs 26 did things.
* doc/lispref/strings.texi (Formatting Strings):
Document behavior of %o, %d, %x, %X on floating-point numbers.
* src/floatfns.c (trunc) [!HAVE_TRUNC]: Rename from emacs_trunc
and make it an extern function, so that editfns.c can use it.
All callers changed.
* test/src/editfns-tests.el (format-%d-float): New test.

* test/src/json-tests.el
(json-parse-with-custom-null-and-false-objects): Skip this test
unless functions being tested exist.

63ba73a Fix documentation of ':propertize' in mode-line-format
22aa665 Reject invalid 5-byte sequences when detecting UTF-8 encoding
0d3c358 Fix 'replace-buffer-contents' in multibyte buffers
c79a627 Update etc/NEWS for mail-source-movemail-program change
63f1dc4 Improve movemail default
0b1a2ae Delete description of deleted Customize functions
fcd66d0 Keep vc-print-log from putting point at buffer end (Bug#31764)

Conflicts:
	etc/NEWS

* src/editfns.c (buffer_chars_equal): Pass a byte position to
BUF_FETCH_CHAR_AS_MULTIBYTE, not a character position.
(Bug#31837)

* test/src/editfns-tests.el (replace-buffer-contents-bug31837):
New test.

* doc/lispref/text.texi (Parsing JSON): Describe new arguments of
json-serialize and json-insert.

* src/json.c (enum json_object_type, struct json_configuration):
Move up in file before first usage.
(lisp_to_json_toplevel, lisp_to_json_toplevel_1, lisp_to_json):
Accept a struct json_configuration*.
(Fjson_serialize, Fjson_insert): Accept multiple args.
(json_parse_args): Accept new boolean configure_object_type.

* test/src/json-tests.el
(json-serialize, json-insert): Update forward decls.
(json-parse-with-custom-null-and-false-objects): Add assertions for
json-serialize.

* doc/lispref/text.texi (Parsing JSON): Describe new :null-object
and :false-object kwargs to json-parse-string and
json-parse-buffer.

* src/json.c
(struct json_configuration): New type.
(json_to_lisp): Accept a struct json_configuration* param.
(json_parse_args): Rename from json_parse_object_type.
(Fjson_parse_string): Rework docstring.
(Fjson_parse_string, Fjson_parse_buffer): Update call to
json_to_lisp.
(syms_of_json): Two new syms, QCnull_object and QCfalse_object.

* test/src/json-tests.el
(json-parse-with-custom-null-and-false-objects): New test.

* src/eval.c (Fdefvaralias): Call `display-warning' if the alias
target has a non-eq value to the variable being aliased.
* test/src/eval-tests.el (defvaralias-overwrite-warning): New test.

* doc/lispref/text.texi (Parsing JSON): Mention plist support.

* src/json.c (lisp_to_json_toplevel_1): Serialize plists to json.
(Fjson_serialize): Mention plists in docstring.
(enum json_object_type): Add json_object_plist.
(json_to_lisp): Parse JSON into plists.
(json_parse_object_type): Consider plists.
(Fjson_parse_string): Mention plists in docstring.
(syms_of_json): New Qplist sym_of_json.
(lisp_to_json): Update comment.

* test/src/json-tests.el (json-serialize/object)
(json-parse-string/object): New plist tests.

* test/src/data-tests.el (data-tests-kill-all-local-variables): New test.

* src/buffer.c (swap_out_buffer_local_variables): Remove.
Fuse the body of its loop into that of reset_buffer_local_variables.
(Fkill_buffer, Fkill_all_local_variables): Don't call it any more.
(reset_buffer_local_variables): Make sure the buffer's local binding
is swapped out before removing it from the alist (bug#30846).
Call watchers before actually killing the var.

* src/data.c (Fmake_local_variable): Simplify.
Use swap_in_global_binding to swap out any local binding, instead of
a mix of find_symbol_value followed by messing with where&found.
Don't call swap_in_symval_forwarding since the currently swapped
binding is never one we've modified.
(Fkill_local_variable): Use swap_in_global_binding rather than messing
with where&found to try and trick find_symbol_value into doing the same.

* src/alloc.c (mark_localized_symbol): 'where' can't be a frame any more.

(cherry picked from commit 3ddff080341580eb6fc18d907181e9cc2301f62d)

* src/alloc.c (free_marker): Remove.
* src/editfns.c (save_restriction_restore):
* src/insdel.c (signal_before_change): Detach the markers from the
buffer when we're done with them instead of calling free_marker on
them.
* test/src/editfns-tests.el (delete-region-undo-markers-1)
(delete-region-undo-markers-2): New tests.

(cherry picked from commit 96b8747d5c5d747af13fd84d8fe0308ef2a0ea7a)