From 06fb8b76208ad380d7d1e592394d3173249f31df Mon Sep 17 00:00:00 2001
From: "F. Jason Park" <jp@neverwas.me>
Date: Wed, 20 Sep 2023 21:40:36 -0700
Subject: [PATCH] Exempt text-scale-mode from erc-scrolltobottom-all

* lisp/erc/erc-goodies.el (erc--scrolltobottom-post-ignore-commands):
New variable, a list of commands that should not trigger a re-scroll.
(erc--scrolltobottom-on-post-command): Don't `recenter' when the
current command appears in `erc--scrolltobottom-post-ignore-commands'.
This fixes a bug that prevented managed recentering when disabling
`text-scale-mode'.  Thanks to Corwin Brust for reporting this.  Note
that this doesn't address any fill-related alignment issues involving
`text-scale-mode'.  Nor does it address likely problems involving the
erroneous restoration of point after the insertion of invisible lines.
(erc-keep-place-enable, erc-keep-place-mode): Adjust hook depth to
fall within reserved interval.
(erc-keep-place-indicator-enable, erc-keep-place-indicator-mode,
erc--keep-place-indicator-on-global-module): Lower hook depth to fall
within reserved interval.  Note that this hook has a buffer-local
value, so all members run after their global counterparts.
(Bug#66073)
---
 lisp/erc/erc-goodies.el | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/lisp/erc/erc-goodies.el b/lisp/erc/erc-goodies.el
index 6eb015fdd64..b77176d8ac7 100644
--- a/lisp/erc/erc-goodies.el
+++ b/lisp/erc/erc-goodies.el
@@ -128,6 +128,11 @@ may be nil, is the number of lines between `window-start' and
 That is, ERC recalculates the window's start instead of blindly
 restoring it.")
 
+;; Unfortunately, this doesn't work when `erc-scrolltobottom-relaxed'
+;; is enabled (scaling up still moves the prompt).
+(defvar erc--scrolltobottom-post-ignore-commands '(text-scale-adjust)
+  "Commands to skip instead of force-scroll on `post-command-hook'.")
+
 (defvar erc--scrolltobottom-relaxed-skip-commands
   '(recenter-top-bottom scroll-down-command)
   "Commands exempt from triggering a stash and restore of `window-start'.
@@ -158,7 +163,8 @@ unnarrowed."
              ((= (nth 2 found)
                  (count-screen-lines (window-start) (point-max)))))
         (set-window-start (selected-window) (nth 1 found))
-      (erc--scrolltobottom-confirm))
+      (unless (memq this-command erc--scrolltobottom-post-ignore-commands)
+        (erc--scrolltobottom-confirm)))
     (setq erc--scrolltobottom-window-info nil)))
 
 (defun erc--scrolltobottom-on-pre-command-relaxed ()
@@ -372,7 +378,7 @@ Put this function on `erc-insert-post-hook' and/or `erc-send-post-hook'."
 ;;;###autoload(autoload 'erc-keep-place-mode "erc-goodies" nil t)
 (define-erc-module keep-place nil
   "Leave point above un-viewed text in other channels."
-  ((add-hook 'erc-insert-pre-hook  #'erc-keep-place 85))
+  ((add-hook 'erc-insert-pre-hook  #'erc-keep-place 65))
   ((remove-hook 'erc-insert-pre-hook  #'erc-keep-place)))
 
 (defcustom erc-keep-place-indicator-style t
@@ -467,7 +473,7 @@ and `keep-place-indicator' in different buffers."
          ((memq 'keep-place erc-modules)
           (erc-keep-place-mode +1))
          ;; Enable a local version of `keep-place-mode'.
-         (t (add-hook 'erc-insert-pre-hook  #'erc-keep-place 85 t)))
+         (t (add-hook 'erc-insert-pre-hook  #'erc-keep-place 65 t)))
    (if (pcase erc-keep-place-indicator-buffer-type
          ('target erc--target)
          ('server (not erc--target))
@@ -490,7 +496,7 @@ That is, ensure the local module can survive a user toggling the
 global one."
   (if erc-keep-place-mode
       (remove-hook 'erc-insert-pre-hook  #'erc-keep-place t)
-    (add-hook 'erc-insert-pre-hook  #'erc-keep-place 85 t)))
+    (add-hook 'erc-insert-pre-hook  #'erc-keep-place 65 t)))
 
 (defun erc-keep-place-move (pos)
   "Move keep-place indicator to current line or POS.