* lisp/eshell/em-basic.el (eshell/echo): Add -E option.

* lisp/eshell/esh-opt.el (eshell--process-option): Raise an error if
an unknown option is encountered, even when :external is nil.

* test/lisp/eshell/esh-opt-tests.el (esh-opt-process-args-test)
(test-eshell-eval-using-options): Add test cases for this.

* doc/misc/ert.texi (Running Tests in Batch Mode): Adjust doc.
* lisp/emacs-lisp/ert.el (ert-run-tests-batch): Allow overriding
the EMACS_TEST_VERBOSE variable by setting it to "" (bug#53313).

This covers the case when a subcommand is to be invoked in more places
than before, for example when a subcommand is concatenated in an
argument.

* lisp/eshell/esh-cmd.el (eshell--find-subcommands): New fuction.
(eshell--invoke-command-directly): Use 'eshell-find-subcommands'.

* test/lisp/eshell/eshell-tests.el
(eshell-test/interp-cmd-external-concat): New test (bug#30725).

* lisp/progmodes/ruby-mode.el (ruby-toggle-block-space-before-parameters):
New user option (bug#53321).
(ruby-do-end-to-brace): Handle it.

* test/lisp/progmodes/ruby-mode-tests.el
(ruby-toggle-block-to-brace-no-space): New test.

* lisp/international/textsec.el (textsec-link-suspicious-p): Scale
back the suspicion -- only warn about texts that contain a full
explicit link.

* lisp/hi-lock.el (hi-lock-read-face-name): Fix the string/symbol
logic.

When an Eshell command contains an asynchronous subcommand (such as
calling an external process), it must be evaluated iteratively.  See
bug#30725.

* lisp/eshell/esh-cmd.el (eshell-invoke-command): Move most of the
logic from here...
(eshell--invoke-command-directly): ... to here. Also add checks for
subcommands.

* test/lisp/eshell/eshell-tests.el (eshell-test--max-subprocess-time):
New variable.
(eshell-wait-for-subprocess): New function.
(eshell-command-result-p): Use 'eshell-wait-for-subprocess'.
(eshell-test/interp-cmd-external): New test (bug#30725).

Fchar_syntax did not convert unibyte characters to multibyte when the
current buffer was unibyte, in contrast to `char-syntax` in
byte-compiled code (bug#53260).

* src/bytecode.c (exec_byte_code): Call out to Fchar_syntax;
the dynamic frequency is too low to justify inlining here, and it
did lead to implementations diverging.
* src/syntax.c (Fchar_syntax): Convert non-ASCII unibyte values to
multibyte.
* test/src/syntax-tests.el (syntax-char-syntax): New test.