* lisp/jsonrpc.el: New file

* test/lisp/jsonrpc-tests.el: New file

* lisp/url/url-http.el
(url-https-proxy-after-change-function): Bind url-http-proxy
to nil around url-http-create-request.

* doc/misc/trampver.texi:
* lisp/net/trampver.el: Change version to "2.4.0".

* lisp/net/tramp-gvfs.el (tramp-gvfs-handler-mounted-unmounted):
Ignore unknown GVFS methods.

* test/lisp/net/tramp-tests.el (tramp-test42-asynchronous-requests):
Tag as :unstable.

* lisp/vc/ediff-util.el (ediff-inferior-compare-regions): Ask user
whether to compare against the ancestor or merge buffer.  Use
read-multiple-choice for A vs B buffer query.

Problem reported by Andy Moreton (Bug#31996).
* src/lisp.h (union specbinding.unwind_array):
Remove unused member func.  Move array after nelts, as this is
likely to generate more efficient code in safe_free, which can
call xfree with the same value either way.
(safe_free): Also handle SPECPDL_UNWIND_AWAY.

On my platform (Fedora 28 x86-64, AMD Phenom II X4 910e) this sped
up a SAFE_FREE-using microbenchmark (string-distance "abc" "abc")
by about 18%, and shrank the Emacs text size by about 0.1%.
* src/callint.c (Fcall_interactively):
* src/callproc.c (call_process):
* src/doc.c (get_doc_string, Fsnarf_documentation):
* src/editfns.c (Freplace_buffer_contents):
* src/emacs-module.c (funcall_module):
* src/eval.c (Flet):
* src/process.c (Fmake_process):
* src/term.c (tty_menu_show):
* src/xdisp.c (safe__call):
* src/xmenu.c (x_menu_show):
Use SAFE_FREE_UNBIND_TO.
* src/data.c (wrong_choice): No need to call SAFE_FREE here.
* src/lisp.h (USE_SAFE_ALLOCA):
* src/regex.c (REGEX_USE_SAFE_ALLOCA):
Do not declare sa_must_free local; no longer needed.
All uses removed.
(SAFE_FREE): Rewrite in terms of safe_free.
(safe_free): New function, optimized to use xfree.
(SAFE_FREE_UNBIND_TO): New macro.
(safe_free_unbind_to): New function.

Fixes: Bug#31951

* lisp/server.el (server-save-buffers-kill-terminal): Only pass
PRED=t to save-some-bufers if ARG in non-nil.