>From 5478db49a2949d2835b79ea460eac11853b190c3 Mon Sep 17 00:00:00 2001
From: "F. Jason Park" <jp@neverwas.me>
Date: Mon, 12 Dec 2022 23:58:03 -0800
Subject: [PATCH 4/5] Set erc-network to a "given" ID instead of failing

* lisp/erc/erc-networks.el (erc-networks--determine): Return the
so-called "given" ID from a non-nil `:id' keyword arg passed to `erc'
or `erc-tls'.
(erc-networks--set-name): Tell the user about falling back to a given
ID when the network can't be determined.  Destroy the connection when
network cannot be determined.  (Bug#59976.)
(erc-networks--ensure-announced): Include the fallback announced name
in the error message.
* test/lisp/erc/erc-networks-tests.el (erc-networks--set-name): Add
dummy server process to test.
---
 lisp/erc/erc-networks.el            | 34 +++++++++++++++++++----------
 test/lisp/erc/erc-networks-tests.el |  2 ++
 2 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/lisp/erc/erc-networks.el b/lisp/erc/erc-networks.el
index 19a7ab8643..51ba54f45c 100644
--- a/lisp/erc/erc-networks.el
+++ b/lisp/erc/erc-networks.el
@@ -60,6 +60,7 @@ erc-session-server
 (declare-function erc-buffer-filter "erc" (predicate &optional proc))
 (declare-function erc-current-nick "erc" nil)
 (declare-function erc-display-error-notice "erc" (parsed string))
+(declare-function erc-display-message "erc" (parsed type buffer msg &rest args))
 (declare-function erc-error "erc" (&rest args))
 (declare-function erc-get-buffer "erc" (target &optional proc))
 (declare-function erc-server-buffer "erc" nil)
@@ -1260,21 +1261,31 @@ erc-networks--determine
                return name)
       (and-let* ((vanity (erc--get-isupport-entry 'NETWORK 'single))
                  ((intern vanity))))
+      (erc-networks--id-given erc-networks--id)
       erc-networks--name-missing-sentinel))
 
-(defun erc-networks--set-name (_proc parsed)
+(defun erc-networks--set-name (proc parsed)
   "Set `erc-network' to the value returned by `erc-networks--determine'.
-Signal an error when the network cannot be determined."
+Signal an error when the network cannot be determined after first
+shutting down the connection."
   ;; Always update (possibly clobber) current value, if any.
   (let ((name (erc-networks--determine)))
+    (when (eq name (erc-networks--id-given erc-networks--id))
+      (let ((m (format "Couldn't determine network. Using given ID `%s'."
+                       name)))
+        (erc-display-message parsed 'notice nil m)))
     (when (eq name erc-networks--name-missing-sentinel)
-      ;; This can happen theoretically, e.g., if you're editing some
-      ;; settings interactively on a proxy service that impersonates IRC
-      ;; but aren't being proxied through to a real network.  The
+      ;; This can happen theoretically, e.g., when adjusting settings
+      ;; on a proxy service that partially impersonates IRC but isn't
+      ;; currently conveying anything through to a real network.  The
       ;; service may send a 422 but no NETWORK param (or *any* 005s).
-      (let ((m (concat "Failed to determine network. Please set entry for "
-                       erc-server-announced-name " in `erc-networks-alist'.")))
+      (let ((m (concat "Failed to determine network.  Please set entry for \""
+                       erc-server-announced-name "\" in `erc-networks-alist'"
+                       " or consider calling `erc-tls' with the keyword `:id'."
+                       "  See Info:\"(erc) Network Identifier\" for more.")))
         (erc-display-error-notice parsed m)
+        (run-hook-with-args 'erc-quit-hook proc)
+        (delete-process proc)
         (erc-error "Failed to determine network"))) ; beep
     (setq erc-network name))
   nil)
@@ -1287,11 +1298,12 @@ erc-networks--ensure-announced
 Copy source (prefix) from MOTD-ish message as a last resort."
   ;; The 004 handler never ran; see 2004-03-10 Diane Murray in change log
   (unless erc-server-announced-name
-    (erc-display-error-notice parsed "Failed to determine server name.")
+    (setq erc-server-announced-name (erc-response.sender parsed))
     (erc-display-error-notice
-     parsed (concat "If this was unexpected, consider reporting it via "
-                    (substitute-command-keys "\\[erc-bug]") "."))
-    (setq erc-server-announced-name (erc-response.sender parsed)))
+     parsed (concat "Failed to determine server name. Using \""
+                    erc-server-announced-name "\" instead."
+                    "  If this was unexpected, consider reporting it via "
+                    (substitute-command-keys "\\[erc-bug]") ".")))
   nil)
 
 (defun erc-unset-network-name (_nick _ip _reason)
diff --git a/test/lisp/erc/erc-networks-tests.el b/test/lisp/erc/erc-networks-tests.el
index fc12bf7ce3..02fc57d4e6 100644
--- a/test/lisp/erc/erc-networks-tests.el
+++ b/test/lisp/erc/erc-networks-tests.el
@@ -1171,6 +1171,8 @@ erc-networks--set-name
     (let (erc-server-announced-name
           (erc--isupport-params (make-hash-table))
           erc-network
+          erc-quit-hook
+          (erc-server-process (erc-networks-tests--create-live-proc))
           calls)
       (erc-mode)
 
-- 
2.38.1