* lisp/erc/erc.el (erc-cmd-default): prevent excess trailing newlines
from being sent.

* test/lisp/erc/erc-tests.el: Update `erc-process-input-line' test to
check for excess line feeds with unknown commands.

* lisp/erc/erc-backend.el (erc-server-reconnecting,
erc--server-reconnecting): obsolete and replace the former with new
internal variant, which carries a simplified meaning.

(erc-server-reconnect-p, erc--server-reconnect-p): Obsolete and
replace the former with an internal function, and change behavior to
disregard `erc-server-reconnecting' when rendering verdict.

(erc-process-sentinel-2): ensure local var `erc--server-reconnecting'
is t when timers are scheduled or firing, and nil otherwise, including
after retries exhausted.  This agrees with the straightforward way
`erc-server-reconnecting' has always been used by `erc-cmd-RECONNECT'.

(erc-server-connect): set `erc--server-reconnecting'.

* lisp/erc/erc.el (erc-cmd-RECONNECT): use `erc--server-reconnecting'
instead of `erc-server-reconnecting'.

* lisp/erc/erc-backend.el (erc-server-reconnecting-p):
Don't consider erc-server-reconnecting when rendering verdict.
(erc-process-sentinel-2): ensure local variable
erc-server-reconnecting is t when timers are scheduled or running and
trying to reconnect, and nil otherwise, including after no retries
remain. Previously, its use and meaning in erc-backend were convoluted
and conflicted with its use in erc-cmd-RECONNECT (bug#50007).

* erc.el (erc-send-input-line): Previously, any line typed into a
query or channel buffer without an explicit user-command
handler (meaning most lines), would be sent twice because a trailing
newline (linefeed) would be appended. This has been verified by
checking IRCd server logs. IRCds won't return an error upon receiving
an empty message, but they also won't forward them to channel
subscribers and DM pals.

* erc-tests.el: Add test for erc-process-input-line, which also
indirectly tests erc-send-input-line. It also tests the command
lookup and dispatch facility (bug#50008).

* lisp/erc/erc-backend.el (define-erc-response-handler): Add
proper indentation.

* doc/misc/erc.texi (ERCVER): Bump to 5.4.1.
* etc/ERC-NEWS: Add entry for 5.4.1 with explanations.
* lisp/erc/erc.el (Version, erc-version): Bump to 5.4.1.
(customize-package-emacs-version-alist): Add entry for 5.4.1.

* lisp/widget.el (define-widget-keywords):
* lisp/vc/pcvs.el (defun-cvs-mode):
* lisp/subr.el (defvar-local):
(defvar-keymap):
* lisp/skeleton.el (define-skeleton):
* lisp/simple.el (define-alternatives):
* lisp/progmodes/gud.el (gdb-script-mode):
* lisp/progmodes/gdb-mi.el (def-gdb-preempt-display-buffer):
(def-gdb-auto-update-trigger):
(def-gdb-auto-update-handler):
(def-gdb-trigger-and-handler):
(def-gdb-thread-buffer-command):
(def-gdb-thread-buffer-simple-command):
(def-gdb-thread-buffer-gud-command):
(def-gdb-set-positive-number):
(def-gdb-memory-format):
(def-gdb-memory-unit):
(def-gdb-memory-show-page):
* lisp/progmodes/compile.el (define-compilation-mode):
* lisp/progmodes/cc-vars.el (defcustom-c-stylevar):
* lisp/obsolete/cl.el (define-setf-expander):
(defsetf):
(define-modify-macro):
* lisp/obsolete/cl-compat.el (defkeyword):
* lisp/net/hmac-def.el (define-hmac-function):
* lisp/international/mule-conf.el (define-iso-single-byte-charset):
* lisp/international/ccl.el (define-ccl-program):
* lisp/image.el (defimage):
* lisp/gnus/gmm-utils.el (defun-gmm):
* lisp/ezimage.el (defezimage):
* lisp/erc/erc.el (define-erc-module):
* lisp/emacs-lisp/shortdoc.el (define-short-documentation-group):
* lisp/emacs-lisp/eieio.el (defclass):
* lisp/emacs-lisp/eieio-compat.el (defgeneric):
(defmethod):
* lisp/emacs-lisp/easy-mmode.el (define-minor-mode):
(define-globalized-minor-mode):
* lisp/emacs-lisp/derived.el (define-derived-mode):
* lisp/emacs-lisp/byte-run.el (defsubst):
(define-obsolete-function-alias):
(define-obsolete-variable-alias):
* lisp/custom.el (defcustom):
(defface):
(defgroup):
(deftheme):
* lisp/cedet/semantic/wisent.el (define-wisent-lexer):
* lisp/cedet/semantic/lex.el (define-lex):
(define-lex-analyzer):
(define-lex-regex-analyzer):
(define-lex-simple-regex-analyzer):
(define-lex-block-analyzer):
(define-lex-keyword-type-analyzer):
(define-lex-sexp-type-analyzer):
(define-lex-regex-type-analyzer):
(define-lex-string-type-analyzer):
(define-lex-block-type-analyzer):
* lisp/cedet/semantic/lex-spp.el
(define-lex-spp-macro-declaration-analyzer):
(define-lex-spp-macro-undeclaration-analyzer):
(define-lex-spp-include-analyzer):
* lisp/cedet/semantic/dep.el
(defcustom-mode-local-semantic-dependency-system-include-path):
* lisp/cedet/semantic/decorate/mode.el
(define-semantic-decoration-style):
* lisp/cedet/mode-local.el (define-child-mode):
(define-overloadable-function):
(define-mode-local-override):
* lisp/calc/calc.el (defcalcmodevar):
(defmath): Explicitly mark all macros that have names that start
with "def" that should indent defunly-like (bug#43329).

* lisp/erc/erc-replace.el:
* lisp/erc/erc-imenu.el:
* lisp/erc/erc-dcc.el: Massage copyright so elpa-admin.el recognizes it

* lisp/erc/erc-dcc.el (erc-dcc-member): Remove XEmacs compat code.
* lisp/erc/erc-goodies.el (erc-move-to-prompt-setup): Doc fix;
remove spurious reference to XEmacs; this is needed also for
Emacs.