* lisp/erc/erc-backend.el (erc-log-p): Remove declaration entirely.
(erc-server-reconnect): Move declaration for `erc-reuse-buffers' here.
(erc-process-sentinel-1): Move `erc-kill-server-buffer-on-quit'
declaration here.
(erc--conceal-prompt): Move `erc-prompt-hidden' declaration here.
(erc-server-INVITE): Move `erc-invitation' declaration here.
(erc-server-PART): Move `erc-kill-buffer-on-part' declaration here.
(erc-server-PRIVMSG): Move declarations for `erc-minibuffer-ignored',
`erc-receive-query-display', `erc-receive-query-display-defer',
`erc--cmem-from-nick-function', `erc-format-nick-function', and
`erc-format-query-as-channel-p' here.
(erc-server-401): Move `erc-whowas-on-nosuchnick' declaration here.
(erc-server-475): Move `erc--called-as-input-p' and
`erc-prompt-for-channel-key' declarations here.
* lisp/erc/erc-common.el (erc-log-p): Remove declaration for
`erc-log-p' and replace with actual definition.
(erc-log-aux): Move `erc-dbuf' declaration from top level into
function body.
* lisp/erc/erc-fill.el (erc-fill--wrap-continued-message-p): Note in
the doc string that this function produces side effects.
* lisp/erc/erc-networks.el (erc-determine-network,
erc-networks--copy-server-buffer-functions): Move some variable
declarations to function body.
(erc-settings, erc-get): Deprecate for now and explain why in doc
strings.  We could deprecate them unconditionally, but they never
provided usable code, and their names are short and valuable.
* lisp/erc/erc.el (tabbar--local-hlf, motif-version-string,
gtk-version-string): Prefer moving these single-serving declarations
to function bodies, if only to make closures from this library less
cluttered when debugging.  This should also help avoid stray
declarations.
(erc-hooks, erc-timer-hook): Revise doc strings.
(erc-log-p): Move definition to erc-common.el.
(erc-cmd-SV): Mimic `emacs-version' and stick with `featurep', here in
combination with special-variable declarations, instead of `boundp' or
similar.
(erc-header-line-uses-tabbar-p): Explain that this has nothing to do
with `tab-bar'.
(erc-update-mode-line-buffer): Only assign when bound.  This has been
verified to work with version 2.0 on EmacsWiki.
* test/lisp/erc/erc-scenarios-base-reconnect.el: Timeouts.
* test/lisp/erc/erc-scenarios-base-renick.el: Timeouts.
* test/lisp/erc/resources/join/network-id/foonet-again.eld: Timeouts.

* lisp/erc/erc-log.el (erc-log-all-but-server-buffers): Use
`erc--server-buffer-p' instead of `erc-server-buffer-p'.  This
replacement is presumed to be relatively "safe" because this function
is unused in the code base and only appears in the doc string for the
option `erc-enable-logging'.
* lisp/erc/erc-match.el (erc-match-message): Leave comment proposing
that `erc--server-buffer-p' should be preferred to
`erc-server-buffer-p'.  Use preferred alias for `erc-server-buffer-p'.
* lisp/erc/erc-notify.el (erc-cmd-NOTIFY): Use preferred alias for
`erc-server-buffer-p', and leave FIXME comment.
* lisp/erc/erc-speedbar.el (erc-speedbar-buttons): Use
`erc--server-buffer-p' instead of `erc-server-buffer-p'.  The logic
here seems simple enough to justify a change, however the absence of
related bug reports is perhaps an argument against this.
* lisp/erc/erc-track.el (erc-track-modified-channels): Use preferred
alias for `erc-server-buffer-p' and leave comment noting possible bug.
* lisp/erc/erc.el (erc-once-with-server-event): Use
`erc--server-buffer-p' instead of `erc-server-buffer-p'.  This change
seems justified because the function sets local hooks that would
otherwise be ignored outside of a server buffer.
(erc-server-buffer-p, erc-server-or-unjoined-channel-buffer-p): Make
the former an obsolete alias for the latter.
(erc--server-buffer-p): New function to replace `erc-server-buffer-p'
internally in new code.  Unlike its predecessor, it returns nil in
parted and kicked channels.
(erc-open-server-buffer-p): Use `erc--server-buffer-p' instead of
`erc-server-buffer-p'.  Given the name and the doc string, breaking
the odd misuse of this function in parted buffers seems justified
because this is clearly a bug fix.  Also, all uses in-tree conform to
the intended behavior as documented.  And a cursory grep of all "erc-"
prefixed packages on MELPA reveals zero instances of this function.
Nor is it used in erbot.
(erc-get-buffer): Mention behavior in doc string regarding parted and
kicked-from channels.
(erc-cmd-GQUIT): Fix wrong-number-of-arguments bug in timer function.
(erc-default-target): Mention behavior regarding unjoined channels.
(erc-kill-query-buffers): Don't use `erc-server-buffer-p'.  This
replacement may break third-party code expecting to leave parted
channels behind, but it seems sane when considering only the lone
internal use in `erc-cmd-QUIT'.
; * test/lisp/erc/resources/join/network-id/foonet.eld: Timeouts.
(Bug#66578)

* lisp/erc/erc-join.el (erc-autojoin-server-match): Favor network
identities, falling back on old definition.
(erc-autojoin--join): Add new helper containing common code from
hookees `erc-autojoin-after-ident' and `erc-autojoin-channels'.
(erc-autojoin-after-ident, erc-autojoin-channels): No longer make a
point of returning nil because the hooks they're registered on,
`erc-nickserv-identified-hook' and `erc-after-connect', don't stop on
success.
(erc-autojoin--mutate): Add helper for `erc-autojoin-add' and
`erc-autojoin-remove'.
(erc-autojoin-add, erc-autojoin-remove): Favor given network
identities, over networks, when matching keys for
`erc-autojoin-channels-alist'.

* test/lisp/erc/erc-scenarios-base-reconnect.el: New file.
* test/lisp/erc/erc-scenarios-join-netid-newcmd-id.el: New file.
* test/lisp/erc/erc-scenarios-join-netid-newcmd.el: New file.
* test/lisp/erc/erc-scenarios-join-netid-recon-id.el: New file.
* test/lisp/erc/erc-scenarios-join-netid-recon.el: New file.
* test/lisp/erc/resources/erc-scenarios-common.el: New file.
* test/lisp/erc/resources/join/legacy/foonet.eld: New file.
* test/lisp/erc/resources/join/network-id/barnet.eld: New file.
* test/lisp/erc/resources/join/network-id/foonet-again.eld: New file.
* test/lisp/erc/resources/join/network-id/foonet.eld: New file.
* test/lisp/erc/resources/join/reconnect/foonet-again.eld: New file.
* test/lisp/erc/resources/join/reconnect/foonet.eld: New file.