Subject: Re: bug#36843: 26.2; ERC lurker feature broken

From: Alex Branham <[email-masked]>
Date: Wed, 04 Sep 2019 09:05:12 -0500

On Tue 27 Aug 2019 at 10:31, Amin Bandali <[email-masked]> wrote:

Is this OK to apply to master? I've been using it locally and seems to
work well.

>>> Date: Sat, 17 Aug 2019 14:09:11 -0400
>>> Subject: [PATCH] Fix erc-lurker-update-status
>>>
>>> Fix erc-lurker-update-status (bug#36843), broken since
>>> d0fcaff514d2be16ccf73817f658318cf85221e3.
>>>
>>> * lisp/erc/erc.el: define `erc-message-parsed', lexically bind it in
>>
>> Instead of "lexically" I believe you actually mean "dynamically"
>> (binding lexically is the cause of the bug).  And I would reformat like
>> this:
>>
>
> Good catch!  I rebased on latest master and reformatted per your
> suggestion.  I’ve attached an updated patch below.
>
> Thanks for your feedback.
>
>>>From 2bc8f35e4a0f76e7b59950738fbfdc3c3e48263c Mon Sep 17 00:00:00 2001
> From: Amin Bandali <[email-masked]>
> Date: Sat, 17 Aug 2019 14:09:11 -0400
> Subject: [PATCH] Fix erc-lurker-update-status (bug#36843)
>
> Broken since 2013-08-22 "* lisp/erc/erc.el: Use lexical-binding".
>
> * lisp/erc/erc.el (erc-message-parsed): New variable.
> (erc-display-message): Dynamically bind it.
> (erc-lurker-update-status): Check it instead of using `parsed'
> directly.  This results in `erc-lurker-state' being properly updated
> to keep track of non-lurkers, and thus `erc-lurker-p' returning
> correct results rather than return t for everyone.
> ---
>  lisp/erc/erc.el | 19 ++++++++++++-------
>  1 file changed, 12 insertions(+), 7 deletions(-)
>
> diff --git a/lisp/erc/erc.el b/lisp/erc/erc.el
> index f5c9decc3a..9ea9e608ac 100644
> --- a/lisp/erc/erc.el
> +++ b/lisp/erc/erc.el
> @@ -2594,6 +2594,8 @@ erc-lurker-cleanup-interval
>  consumption of lurker state during long Emacs sessions and/or ERC
>  sessions with large numbers of incoming PRIVMSGs.")
>  
> +(defvar erc-message-parsed)
> +
>  (defun erc-lurker-update-status (_message)
>    "Update `erc-lurker-state' if necessary.
>  
> @@ -2603,18 +2605,20 @@ erc-lurker-update-status
>  current time.  Otherwise, take no action.
>  
>  This function depends on the fact that `erc-display-message'
> -dynamically binds `parsed', which is used to check if the current
> -message is a PRIVMSG and to determine its sender.  See also
> -`erc-lurker-trim-nicks' and `erc-lurker-ignore-chars'.
> +dynamically binds `erc-message-parsed', which is used to check if
> +the current message is a PRIVMSG and to determine its sender.
> +See also `erc-lurker-trim-nicks' and `erc-lurker-ignore-chars'.
>  
>  In order to limit memory consumption, this function also calls
>  `erc-lurker-cleanup' once every `erc-lurker-cleanup-interval'
>  updates of `erc-lurker-state'."
> -  (when (and (boundp 'parsed) (erc-response-p parsed))
> -    (let* ((command (erc-response.command parsed))
> +  (when (and (boundp 'erc-message-parsed)
> +	     (erc-response-p erc-message-parsed))
> +    (let* ((command (erc-response.command erc-message-parsed))
>             (sender
>              (erc-lurker-maybe-trim
> -             (car (erc-parse-user (erc-response.sender parsed)))))
> +             (car (erc-parse-user
> +		   (erc-response.sender erc-message-parsed)))))
>             (server
>              (erc-canonicalize-server-name erc-server-announced-name)))
>        (when (equal command "PRIVMSG")
> @@ -2704,7 +2708,8 @@ erc-display-message
>  See also `erc-format-message' and `erc-display-line'."
>    (let ((string (if (symbolp msg)
>                      (apply #'erc-format-message msg args)
> -                  msg)))
> +                  msg))
> +	(erc-message-parsed parsed))
>      (setq string
>            (cond
>             ((null type)