Subject: bug#59501: [PATCH] rcirc: Issue with printing messages in the wrong place

From: Thuna <[email-masked]>
Date: Wed, 23 Nov 2022 04:37:37 +0100

>From 43bd8eb367f33a022fcc6554102ca38204296e7f Mon Sep 17 00:00:00 2001
From: Thuna <[email-masked]>
Date: Wed, 23 Nov 2022 04:14:36 +0100
Subject: [PATCH] rcirc: Fix messages printing in the wrong place

* lisp/net/rcirc.el (rcirc-send-message): Print the message before
sending it to the server.
(rcirc-print): Get the time with subsecond precision.
* lisp/calendar/parse-time.el (parse-time-string
parse-iso8601-time-string): Accept optional second FORM arguments,
with the same meaning as in `decode-time'.  Mention as such in the
docstring.
---
 lisp/calendar/parse-time.el | 16 ++++++++++------
 lisp/net/rcirc.el           |  6 +++---
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/lisp/calendar/parse-time.el b/lisp/calendar/parse-time.el
index f3ad513925..15713980cb 100644
--- a/lisp/calendar/parse-time.el
+++ b/lisp/calendar/parse-time.el
@@ -147,7 +147,7 @@ parse-time-rules
 ;;;###autoload(put 'parse-time-rules 'risky-local-variable t)
 
 ;;;###autoload
-(defun parse-time-string (string)
+(defun parse-time-string (string &optional form)
   "Parse the time in STRING into (SEC MIN HOUR DAY MON YEAR DOW DST TZ).
 STRING should be an ISO 8601 time string, e.g., \"2020-01-15T16:12:21-08:00\",
 or something resembling an RFC 822 (or later) date-time, e.g.,
@@ -156,9 +156,11 @@ parse-time-string
 return a \"likely\" value even for somewhat malformed strings.
 The values returned are identical to those of `decode-time', but
 any unknown values other than DST are returned as nil, and an
-unknown DST value is returned as -1."
+unknown DST value is returned as -1.
+
+See ‘decode-time’ for the meaning of FORM."
   (condition-case ()
-      (iso8601-parse string)
+      (iso8601-parse string form)
     (wrong-type-argument
      (let ((time (list nil nil nil nil nil nil nil -1 nil))
 	   (temp (parse-time-tokenize (downcase string))))
@@ -199,12 +201,14 @@ parse-time-string
 		     (setf (nth (pop slots) time) new-val))))))))
        time))))
 
-(defun parse-iso8601-time-string (date-string)
+(defun parse-iso8601-time-string (date-string &optional form)
   "Parse an ISO 8601 time string, such as \"2020-01-15T16:12:21-08:00\".
 Fall back on parsing something resembling an RFC 822 (or later) date-time.
 This function is like `parse-time-string' except that it returns
-a Lisp timestamp when successful."
-  (when-let ((time (parse-time-string date-string)))
+a Lisp timestamp when successful.
+
+See ‘decode-time’ for the meaning of FORM."
+  (when-let ((time (parse-time-string date-string form)))
     (encode-time time)))
 
 (provide 'parse-time)
diff --git a/lisp/net/rcirc.el b/lisp/net/rcirc.el
index 99b9888fda..1fdf41a35e 100644
--- a/lisp/net/rcirc.el
+++ b/lisp/net/rcirc.el
@@ -1233,9 +1233,9 @@ rcirc-send-message
   (let ((response (if noticep "NOTICE" "PRIVMSG")))
     (rcirc-get-buffer-create process target)
     (dolist (msg (rcirc-split-message message))
-      (rcirc-send-string process response target : msg)
       (unless silent
-        (rcirc-print process (rcirc-nick process) response target msg)))))
+        (rcirc-print process (rcirc-nick process) response target msg))
+      (rcirc-send-string process response target : msg))))
 
 (defvar-local rcirc-input-ring nil
   "Ring object for input.")
@@ -2034,7 +2034,7 @@ rcirc-print
                (not (string= sender (rcirc-nick process))))
     (let* ((buffer (rcirc-target-buffer process sender response target text))
            (time (if-let ((time (rcirc-get-tag "time")))
-                     (parse-iso8601-time-string time)
+                     (parse-iso8601-time-string time t)
                    (current-time)))
            (inhibit-read-only t))
       (with-current-buffer buffer
-- 
2.37.4

I have occasionally had replies show before my messages, so I 
decided to look into it.   It looks like rcirc looks at the time 
of the message, compares it to the `rcirc-time' text property of 
other messages, and places it so that the property is properly 
ordered. 
 
> ============================= Disregard this, the patch does not 
> fix it.  I decided to keep it in because the problem is still 
> possible, but not it's not what's responsible for this specific 
> issue. 
The issue with this is, because the recieved messages' precision 
can be less than the sent messages' precision (`current-time' 
returns the time down to milliseconds but servers may choose to 
only keep it down to seconds), this causes some issues when a 
message is recieved after a message was sent but still within the 
same second. 
> ============================= 
 
An example of this, with the value of the text property 
`rcirc-time' at the left of the message itself, is: 
> (25469 29640 874652 270000)   > 02:13 <thuna`> ,ping
> (25469 29641)                 > 02:13 <fsbot> ␕
> (25469 29642 502966 649000)   > 02:13 <thuna`> ,ping
> (25469 29643)                 > 02:13 <fsbot> ␕
> (25469 29643 755653 540000)   > 02:13 <thuna`> ,ping
> (25469 29644)                 > 02:13 <fsbot> ␕
> (25469 29645)                 > 02:13 <fsbot> ␕
> (25469 29645 103860 988000)   > 02:13 <thuna`> ,ping

As you can see, the response to the last ping arrived after the ping
itself, but because of the precision difference, rcirc sorted the
messages wrong.

The issue was with `parse-time-string'.  It (and by proxy
`parse-iso8601-time-string'), uses `iso8601-parse' with nil FORM,
resulting in the subsecond precision being thrown out.  To fix this, I
added FORM arguments to those two functions as well.