Remove obsolete server buffers on MOTD in erc-track

* lisp/erc/erc-networks.el
(erc-networks--copy-server-buffer-functions): New internal hook
through which modules can perform housekeeping when server buffers
belonging to the same network context are merged.
(erc-networks--copy-over-server-buffer-contents): Run new internal
hook `erc-networks--copy-server-buffer-functions'.
* lisp/erc/erc-track.el (erc-track-enable, erc-track-disable): Manage
membership in `erc-networks--copy-server-buffer-functions' hook.
(erc-track--replace-killed-buffer): New function to replace server
buffer being killed in `erc-modified-channels-alist'.
* test/lisp/erc/erc-scenarios-base-association.el
(erc-scenarios-networks-merge-server-track): New test.
* test/lisp/erc/resources/networks/merge-server/track.eld: New test
data.  (Bug#60560.)

1 files changed, 44 insertions, 0 deletions

diff --git a/test/lisp/erc/resources/networks/merge-server/track.eld b/test/lisp/erc/resources/networks/merge-server/track.eld
new file mode 100644
index 00000000000..4a97f92f722
--- /dev/null
+++ b/test/lisp/erc/resources/networks/merge-server/track.eld
@@ -0,0 +1,44 @@
+;; -*- mode: lisp-data; -*-
+((nick 10 "NICK tester"))
+((user 10 "USER user 0 * :unknown")
+ (0.00 ":irc.example.net NOTICE * :*** Looking up your hostname...")
+ (0.01 ":irc.example.net NOTICE tester :*** Could not resolve your hostname: Domain not found; using your IP address (10.0.2.100) instead.")
+ (0.10 ":irc.example.net 001 tester :Welcome to the FooNet IRC Network tester!user@10.0.2.100")
+ (0.02 ":irc.example.net 002 tester :Your host is irc.example.net, running version InspIRCd-3")
+ (0.02 ":irc.example.net 003 tester :This server was created 05:58:57 Jan 04 2023")
+ (0.01 ":irc.example.net 004 tester irc.example.net InspIRCd-3 BIRcgikorsw ACHIKMORTXabcefghijklmnopqrstvz :HIXabefghjkloqv")
+ (0.00 ":irc.example.net 005 tester ACCEPT=30 AWAYLEN=200 BOT=B CALLERID=g CASEMAPPING=ascii CHANLIMIT=#:20 CHANMODES=IXbeg,k,Hfjl,ACKMORTcimnprstz CHANNELLEN=64 CHANTYPES=# ELIST=CMNTU ESILENCE=CcdiNnPpTtx EXCEPTS=e :are supported by this server")
+ (0.02 ":irc.example.net 005 tester EXTBAN=,ACORTUacjrwz HOSTLEN=64 INVEX=I KEYLEN=32 KICKLEN=255 LINELEN=512 MAXLIST=I:100,X:100,b:100,e:100,g:100 MAXTARGETS=20 MODES=20 MONITOR=30 NAMELEN=128 NAMESX NETWORK=FooNet :are supported by this server")
+ (0.01 ":irc.example.net 005 tester NICKLEN=30 PREFIX=(qaohv)~&@%+ SAFELIST SILENCE=32 STATUSMSG=~&@%+ TOPICLEN=307 UHNAMES USERIP USERLEN=10 USERMODES=,,s,BIRcgikorw WHOX :are supported by this server")
+ (0.01 ":irc.example.net 251 tester :There are 2 users and 0 invisible on 2 servers")
+ (0.01 ":irc.example.net 253 tester 1 :unknown connections")
+ (0.01 ":irc.example.net 254 tester 1 :channels formed")
+ (0.00 ":irc.example.net 255 tester :I have 2 clients and 1 servers")
+ (0.00 ":irc.example.net 265 tester :Current local users: 2  Max: 3")
+ (0.00 ":irc.example.net 266 tester :Current global users: 2  Max: 3")
+ (0.00 ":irc.example.net 375 tester :irc.example.net message of the day")
+ (0.00 ":irc.example.net 372 tester :  Have fun with the image!")
+ (0.00 ":irc.example.net 376 tester :End of message of the day."))
+
+((mode 10 "MODE tester +i")
+ (0.00 ":irc.example.net 501 tester x :is not a recognised user mode.")
+ (0.00 ":NickServ!NickServ@services.int NOTICE tester :Welcome to FooNet, tester! Here on FooNet, we provide services to enable the registration of nicknames and channels! For details, type \2/msg NickServ help\2 and \2/msg ChanServ help\2.")
+ (0.02 ":tester!user@10.0.2.100 MODE tester :+i"))
+
+((join 10 "JOIN #chan")
+ (0.01 ":tester!user@10.0.2.100 JOIN :#chan"))
+
+((mode 10 "MODE #chan")
+ (0.01 ":irc.example.net 353 tester = #chan :@alice bob tester")
+ (0.01 ":irc.example.net 366 tester #chan :End of /NAMES list.")
+ (0.00 ":alice!alice@0::1 PRIVMSG #chan :tester, welcome!")
+ (0.02 ":bob!bob@0::1 PRIVMSG #chan :tester, welcome!")
+ (0.02 ":irc.example.net 324 tester #chan :+nt")
+ (0.01 ":irc.example.net 329 tester #chan :1672811954")
+ (0.07 ":alice!alice@0::1 PRIVMSG #chan :bob: This afternoon, sir ? well, she shall be there.")
+ (0.05 ":bob!bob@0::1 PRIVMSG #chan :alice: The hour that fools should ask."))
+
+((quit 10 "QUIT :\2ERC\2")
+ (0.04 "ERROR :Closing link: (user@10.0.2.100) [Quit: \2ERC\2]"))
+
+((drop 1 DROP))