master c6eb114: ERC: NickServ: Prompt for password last, overall simplifications (bug#46777)

[Amin Bandali]

branch: master
commit c6eb114a42922af18818dce7317238e0af776958
Author: Olivier Certner <olce.emacs@certner.fr>
Commit: Amin Bandali <bandali@gnu.org>

    ERC: NickServ: Prompt for password last, overall simplifications (bug#46777)
    
    When 'erc-prompt-for-nickserv-password' is non-nil, don't ignore the
    other forms of identification.  Instead, process them first, and
    prompt for the password last.  Separate concerns (determination of the
    nick to use, of the password to use, and actual message sending).
    
    Note that the user can be interactively prompted for a password on
    reception of a NickServ request, as before (on
    'erc-prompt-for-nickserv-password').
    
    * lisp/erc/erc-services.el (erc-nickserv-identify): Make the password
    argument optional (and don't prompt for it interactively).  Further,
    now take the nick to use for identification (interactively, ask for
    it, defaulting to the current one).  Move the actual message sending
    into the new 'erc-nickserv-send-identify' function, and the password
    prompting into 'erc-nickserv-get-password'.
    
    (erc-nickserv-send-identify): New function containing the code for
    sending the identify message to NickServ, given the nick and password.
    
    (erc-nickserv-get-password): Try each password source in turn, in the
    following order: 'erc-nickserv-passwords', auth-source (if
    'erc-use-auth-source-for-nickserv-password' is non-nil), and in the
    end prompt the user interactively (if
    'erc-prompt-for-nickserv-password' is non-nil).  If one source returns
    a string, the function returns it, or nil if the string is empty.
    
    (erc-nickserv-call-identify-function): Declare obsolete, but retain
    for backward compatibility.  Prefer invoking 'erc-nickserv-identify'
    directly instead.
    
    (erc-nickserv-identify-autodetect, erc-nickserv-identify-on-connect)
    (erc-nickserv-identify-on-nick-change): Call 'erc-nickserv-identify'
    directly ('erc-nickserv-call-identify-function' has been obsoleted).
    For the last two functions, remove the redundant checks on the
    NickServ identification flags (additionally, it is doubtful they have
    any measurable impact on performance).
    
    * etc/NEWS: Announce the change.
    
    Co-authored-by: F. Jason Park <jp@neverwas.me>
---
 etc/NEWS                 |  15 ++++-
 lisp/erc/erc-services.el | 168 +++++++++++++++++++++++++++--------------------
 2 files changed, 110 insertions(+), 73 deletions(-)

diff --git a/etc/NEWS b/etc/NEWS
index 17c42ce..eee6d25 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -2632,13 +2632,22 @@ Interactively, 'C-u C-c C-o' triggers this new optional 
behavior.
 ** ERC
 
 ---
-*** erc-services.el now supports NickServ passwords from auth-source.
+*** NickServ passwords can now be retrieved from auth-source.
 The 'erc-use-auth-source-for-nickserv-password' user option enables
 querying auth-source for NickServ passwords.  To enable this, add the
 following to your init file:
 
-    (setq erc-prompt-for-nickserv-password nil
-          erc-use-auth-source-for-nickserv-password t)
+    (setq erc-use-auth-source-for-nickserv-password t)
+
+---
+*** NickServ identification now prompts for password last.
+When 'erc-prompt-for-nickserv-password' is non-nil, the user used to
+be unconditionally prompted interactively for a password, regardless
+of the value of 'erc-nickserv-passwords', which was effectively
+ignored (same for the new
+'erc-use-auth-source-for-nickserv-password').  This limitation is now
+lifted, and the user is interactively prompted last, after the other
+identification methods have run.
 
 ---
 *** The '/ignore' command will now ask for a timeout to stop ignoring the user.
diff --git a/lisp/erc/erc-services.el b/lisp/erc/erc-services.el
index 61006e0..adb3f52 100644
--- a/lisp/erc/erc-services.el
+++ b/lisp/erc/erc-services.el
@@ -169,9 +169,8 @@ You can also use \\[erc-nickserv-identify-mode] to change 
modes."
 
 (defcustom erc-use-auth-source-for-nickserv-password nil
   "Query auth-source for a password when identifiying to NickServ.
-This option has an no effect if `erc-prompt-for-nickserv-password'
-is non-nil, and passwords from `erc-nickserv-passwords' take
-precedence."
+Passwords from `erc-nickserv-passwords' take precedence.  See
+function `erc-nickserv-get-password'."
   :version "28.1"
   :type 'boolean)
 
@@ -405,85 +404,114 @@ password for this nickname, otherwise try to send it 
automatically."
                 identify-regex
                 (string-match identify-regex msg))
        (erc-log "NickServ IDENTIFY request detected")
-       (erc-nickserv-call-identify-function nick)
+        (erc-nickserv-identify nil nick)
        nil))))
 
 (defun erc-nickserv-identify-on-connect (_server nick)
   "Identify to Nickserv after the connection to the server is established."
-  (unless (or (and (null erc-nickserv-passwords)
-                   (null erc-prompt-for-nickserv-password)
-                   (null erc-use-auth-source-for-nickserv-password))
-              (and (eq erc-nickserv-identify-mode 'both)
-                   (erc-nickserv-alist-regexp (erc-network))))
-    (erc-nickserv-call-identify-function nick)))
+  (unless (and (eq erc-nickserv-identify-mode 'both)
+               (erc-nickserv-alist-regexp (erc-network)))
+    (erc-nickserv-identify nil nick)))
 
 (defun erc-nickserv-identify-on-nick-change (nick _old-nick)
   "Identify to Nickserv whenever your nick changes."
-  (unless (or (and (null erc-nickserv-passwords)
-                   (null erc-prompt-for-nickserv-password)
-                   (null erc-use-auth-source-for-nickserv-password))
-              (and (eq erc-nickserv-identify-mode 'both)
-                   (erc-nickserv-alist-regexp (erc-network))))
-    (erc-nickserv-call-identify-function nick)))
-
-(defun erc-nickserv-get-password (nickname)
-  "Return the password for NICKNAME from configured sources.
-
-It uses `erc-nickserv-passwords' and additionally auth-source
-when `erc-use-auth-source-for-nickserv-password' is not nil."
-  (or
-   (when erc-nickserv-passwords
-     (cdr (assoc nickname
-                 (nth 1 (assoc (erc-network)
-                               erc-nickserv-passwords)))))
-   (when erc-use-auth-source-for-nickserv-password
-     (let* ((secret (nth 0 (auth-source-search
-                            :max 1 :require '(:secret)
-                            :host (erc-with-server-buffer erc-session-server)
-                            :port (format ; ensure we have a string
-                                   "%s" (erc-with-server-buffer 
erc-session-port))
-                            :user nickname))))
-       (when secret
-         (let ((passwd (plist-get secret :secret)))
-           (if (functionp passwd) (funcall passwd) passwd)))))))
-
-(defun erc-nickserv-call-identify-function (nickname)
-  "Call `erc-nickserv-identify'.
-Either call it interactively or run it with NICKNAME's password,
-depending on the value of `erc-prompt-for-nickserv-password'."
-  (if erc-prompt-for-nickserv-password
-      (call-interactively 'erc-nickserv-identify)
-    (erc-nickserv-identify (erc-nickserv-get-password nickname))))
+  (unless (and (eq erc-nickserv-identify-mode 'both)
+               (erc-nickserv-alist-regexp (erc-network)))
+    (erc-nickserv-identify nil nick)))
+
+(defun erc-nickserv-get-password (nick)
+  "Return the password for NICK from configured sources.
+First, a password for NICK is looked up in
+`erc-nickserv-passwords'.  Then, it is looked up in auth-source
+if `erc-use-auth-source-for-nickserv-password' is not nil.
+Finally, interactively prompt the user, if
+`erc-prompt-for-nickserv-password' is true.
+
+As soon as some source returns a password, the sequence of
+lookups stops and this function returns it (or returns nil if it
+is empty).  Otherwise, no corresponding password was found, and
+it returns nil."
+  (let (network server port)
+    ;; Fill in local vars, switching to the server buffer once only
+    (erc-with-server-buffer
+     (setq network erc-network
+           server erc-session-server
+           port erc-session-port))
+    (let ((ret
+           (or
+            (when erc-nickserv-passwords
+              (cdr (assoc nick
+                          (cl-second (assoc network
+                                            erc-nickserv-passwords)))))
+            (when erc-use-auth-source-for-nickserv-password
+              (let ((secret (cl-first (auth-source-search
+                                       :max 1 :require '(:secret)
+                                       :host server
+                                       ;; Ensure a string for :port
+                                       :port (format "%s" port)
+                                       :user nick))))
+                (when secret
+                  (let ((passwd (plist-get secret :secret)))
+                    (if (functionp passwd) (funcall passwd) passwd)))))
+            (when erc-prompt-for-nickserv-password
+              (read-passwd
+               (format "NickServ password for %s on %s (RET to cancel): "
+                       nick network))))))
+      (when (and ret (not (string= ret "")))
+        ret))))
 
 (defvar erc-auto-discard-away)
 
-;;;###autoload
-(defun erc-nickserv-identify (password)
+(defun erc-nickserv-send-identify (nick password)
   "Send an \"identify <PASSWORD>\" message to NickServ.
-When called interactively, read the password using `read-passwd'."
+Returns t if the message could be sent, nil otherwise."
+  (let* ((erc-auto-discard-away nil)
+         (network (erc-network))
+         (nickserv-info (assoc network erc-nickserv-alist))
+         (nickserv (or (erc-nickserv-alist-nickserv nil nickserv-info)
+                       "NickServ"))
+         (identify-word (or (erc-nickserv-alist-ident-keyword
+                             nil nickserv-info)
+                            "IDENTIFY"))
+         (nick (if (erc-nickserv-alist-use-nick-p nil nickserv-info)
+                   (concat nick " ")
+                 ""))
+         (msgtype (or (erc-nickserv-alist-ident-command nil nickserv-info)
+                      "PRIVMSG")))
+    (erc-message msgtype
+                 (concat nickserv " " identify-word " " nick password))))
+
+(defun erc-nickserv-call-identify-function (nickname)
+  "Call `erc-nickserv-identify' with NICKNAME."
+  (declare (obsolete erc-nickserv-identify "28.1"))
+  (erc-nickserv-identify nil nickname))
+
+;;;###autoload
+(defun erc-nickserv-identify (&optional password nick)
+  "Identify to NickServ immediately.
+Identification will either use NICK or the current nick if not
+provided, and some password obtained through
+`erc-nickserv-get-password' (which see).  If no password can be
+found, an error is reported trough `erc-error'.
+
+Interactively, the user will be prompted for NICK, an empty
+string meaning to default to the current nick.
+
+Returns t if the identify message could be sent, nil otherwise."
   (interactive
-   (list (read-passwd
-         (format "NickServ password for %s on %s (RET to cancel): "
-                 (erc-current-nick)
-                 (or (and (erc-network)
-                          (symbol-name (erc-network)))
-                     "Unknown network")))))
-  (when (and password (not (string= "" password)))
-    (let* ((erc-auto-discard-away nil)
-          (network (erc-network))
-          (nickserv-info (assoc network erc-nickserv-alist))
-          (nickserv (or (erc-nickserv-alist-nickserv nil nickserv-info)
-                        "NickServ"))
-          (identify-word (or (erc-nickserv-alist-ident-keyword
-                              nil nickserv-info)
-                             "IDENTIFY"))
-          (nick (if (erc-nickserv-alist-use-nick-p nil nickserv-info)
-                    (concat (erc-current-nick) " ")
-                  ""))
-          (msgtype (or (erc-nickserv-alist-ident-command nil nickserv-info)
-                       "PRIVMSG")))
-      (erc-message msgtype
-                  (concat nickserv " " identify-word " " nick password)))))
+   (list
+    nil
+    (read-from-minibuffer "Nickname: " nil nil nil
+                          'erc-nick-history-list (erc-current-nick))))
+  (unless (and nick (not (string= nick "")))
+    (setq nick (erc-current-nick)))
+  (unless password
+    (setq password (erc-nickserv-get-password nick)))
+  (if password
+      (erc-nickserv-send-identify nick password)
+    (erc-error "Cannot find a password for nickname %s"
+               nick)
+    nil))
 
 (provide 'erc-services)