From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: "F. Jason Park" <jp@neverwas.me>
Date: Tue, 19 Oct 2021 22:53:03 -0700
Subject: [PATCH 08/28] Add eventual replacement for erc-default-recipients

* lisp/erc/erc.el (erc--target, erc--buffer-target): Add new defstruct
available locally through latter in all target buffers.
(erc-open): Create above items in non server buffers.

* lisp/erc/erc-backend.el (erc-server-NICK): Recreate
`erc--buffer-target' when necessary.
---
 lisp/erc/erc-backend.el    |  4 ++--
 lisp/erc/erc.el            | 29 +++++++++++++++++++++++++++++
 test/lisp/erc/erc-tests.el | 11 +++++++++++
 3 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/lisp/erc/erc-backend.el b/lisp/erc/erc-backend.el
index dedc041f51..e7256cd793 100644
--- a/lisp/erc/erc-backend.el
+++ b/lisp/erc/erc-backend.el
@@ -1388,8 +1388,8 @@ define-erc-response-handler
       (erc-buffer-filter
        (lambda ()
          (when (equal (erc-default-target) nick)
-           (setq erc-default-recipients
-                 (cons nn (cdr erc-default-recipients)))
+           (setq erc-default-recipients (cons nn (cdr erc-default-recipients))
+                 erc--buffer-target (erc--target-from-string nn))
            (rename-buffer nn t)         ; bug#12002
            (erc-update-mode-line)
            (cl-pushnew (current-buffer) bufs))))
diff --git a/lisp/erc/erc.el b/lisp/erc/erc.el
index ae386cc096..0c2cbb9d82 100644
--- a/lisp/erc/erc.el
+++ b/lisp/erc/erc.el
@@ -1352,6 +1352,34 @@ define-erc-module
        (put ',enable  'definition-name ',name)
        (put ',disable 'definition-name ',name))))
 
+;; ERASE ME: instead of this, we could have an erc--target-channel
+;; type and (:include erc--target), but then erc--target-channel-p
+;; would be no simpler than what we have here.
+(cl-defstruct (erc--target
+               (:constructor
+                erc--target-from-string
+                (string
+                 &aux
+                 (symbol (intern (erc-downcase string)))
+                 (channel-p (and (erc-channel-p string) t))
+                 (local-p (and channel-p
+                               (erc-valid-local-channel-p string)
+                               t)))))
+  ;; Use local-p instead of localp so accessor is hyphenated.
+  (string "" :type string :documentation "Received name of target.")
+  (symbol nil :type symbol :documentation "Case-mapped name as symbol.")
+  (channel-p nil :type boolean :documentation "Whether we're a channel.")
+  (local-p nil :type boolean :documentation "Whether we're a local channel."))
+
+(defvar-local erc--buffer-target nil
+  "Info about a buffer's target, if any.")
+
+;; Temporary internal getter to ease transition to `erc--target' everywhere.
+(defun erc--default-target ()
+  "Return target string or nil."
+  (when erc--buffer-target
+    (erc--target-string erc--buffer-target)))
+
 (defun erc-once-with-server-event (event f)
   "Run function F the next time EVENT occurs in the `current-buffer'.
 
@@ -2042,6 +2070,7 @@ erc-open
     (set-marker erc-insert-marker (point))
     ;; stack of default recipients
     (setq erc-default-recipients tgt-list)
+    (setq erc--buffer-target (and channel (erc--target-from-string channel)))
     (setq erc-server-current-nick nil)
     ;; Initialize erc-server-users and erc-channel-users
     (if connect
diff --git a/test/lisp/erc/erc-tests.el b/test/lisp/erc/erc-tests.el
index e1454305c2..d9112c7b0a 100644
--- a/test/lisp/erc/erc-tests.el
+++ b/test/lisp/erc/erc-tests.el
@@ -227,6 +227,17 @@ erc-local-channel-p
       (should-not (erc-valid-local-channel-p "#chan"))
       (should (erc-valid-local-channel-p "&local")))))
 
+(ert-deftest erc--target-from-string ()
+  (should (equal (erc--target-from-string "#chan")
+                 #s(erc--target "#chan" \#chan t nil)))
+
+  (should (equal (erc--target-from-string "Bob")
+                 #s(erc--target "Bob" bob nil nil)))
+
+  (let ((erc-isupport-parameters '((CHANTYPES "#&"))))
+    (should (equal (erc--target-from-string "&Bitlbee")
+                   #s(erc--target "&Bitlbee" &bitlbee t t)))))
+
 (ert-deftest erc-ring-previous-command-base-case ()
   (ert-info ("Create ring when nonexistent and do nothing")
     (let (erc-input-ring
-- 
2.31.1