bug#32470: rcirc-debug: ignore read-only; do not move point if mid-buffer; use %F

[Ivan Shmakov]

Package:  emacs
Severity: wishlist
Tags: patch

        I find it quite convenient to be able to make the *rcirc debug*
        buffer read-only, so that I won’t be able to change it by
        accident.  This of course requires the rcirc-debug function to
        use inhibit-read-only.

        Another usability tweak is to restore point after insertion –
        unless it was at the end of the (visible portion of the) buffer
        before.  (Hence allowing the buffer to scroll normally after
        end-of-buffer is used.)

        Also, while we’re at, %Y-%m-%d can be replaced with the
        equivalent %F in the format-time-string argument; and concat
        is useless as ‘insert’ effectively concatenates its string
        arguments already.

        I’m somewhat unsure if this change is NEWS-worthy; if so,
        I suggest the following entry.

** rcirc

+++
*** The 'rcirc-debug-buffer' can now be made read-only; it will be
ignored when adding debug text to it.  Also, the point will not be
moved, unless it's set to the end of the visible portion of the buffer.

        Please thus consider the patch MIMEd.

-- 
FSF associate member #7257  np. Funiculì, funiculà — Luciano Pavarotti

From: Ivan Shmakov <ivan@siamics.net>
Subject: Improve user convenience of the rcirc debug buffer
Date: Sat, 18 Aug 2018 08:57:08 +0000

* lisp/net/rcirc.el (rcirc-debug): Ignore rcirc-debug-buffer read-only
status.  Restore point after insertion unless it was at the end.
Replace %Y-%m-%d with the equivalent %F in format-time-string; remove
useless concat.  (Bug#-XXX-)
---

--- a/lisp/net/rcirc.el
+++ b/lisp/net/rcirc.el
@@ -670,16 +670,24 @@
   "If non-nil, write information to `rcirc-debug-buffer'.")
 (defun rcirc-debug (process text)
   "Add an entry to the debug log including PROCESS and TEXT.
-Debug text is written to `rcirc-debug-buffer' if `rcirc-debug-flag'
-is non-nil."
+Debug text is appended to `rcirc-debug-buffer' if `rcirc-debug-flag'
+is non-nil.
+
+For convenience, the read-only state of the debug buffer is ignored.
+When the point is at the end of the visible portion of the buffer, it
+is moved to after the text inserted.  Otherwise the point is not moved."
   (when rcirc-debug-flag
     (with-current-buffer (get-buffer-create rcirc-debug-buffer)
-      (goto-char (point-max))
-      (insert (concat
-              "["
-              (format-time-string "%Y-%m-%dT%T ") (process-name process)
-              "] "
-              text)))))
+      (let ((old (set-marker (make-marker) (point))))
+        (set-marker-insertion-type old t)
+        (goto-char (point-max))
+        (let ((inhibit-read-only t))
+          (terpri (current-buffer) t)
+          (insert "["
+                  (format-time-string "%FT%T ") (process-name process)
+                  "] "
+                  text))
+        (goto-char old)))))
 
 (define-obsolete-variable-alias 'rcirc-sentinel-hooks
   'rcirc-sentinel-functions "24.3")