From 89df65e8434ce18c88c0c4e1cc91eaef2d1e4137 Mon Sep 17 00:00:00 2001
From: David Taylor <david@taylorhq.com>
Date: Mon, 20 Jan 2025 15:16:53 +0000
Subject: [PATCH] FIX: Avoid possible rendering infinite-loop in post-menu
 (#30873)

ff815384 introduced a modifier which changes tracked state. If the
conditions are correct, this can cause an infinite re-rendering loop.
One example is [here](https://meta.discourse.org/t/346215/4), although
there are other non-dev-tools things which could trigger this kind of
loop. As a general rule, modifiers should not change tracked state.

This commit changes the approach to match the rest of the new-post-menu
assumptions: instead of trying to modify `collapsed` at runtime, the
rendering of individual buttons has the `>1` logic. That matches the
existing logic
[here](https://github.com/discourse/discourse/blob/89ff7d51e6/app/assets/javascripts/discourse/app/components/post/menu.gjs#L392C18-L394C6).
---
 .../discourse/app/components/post/menu.gjs      | 17 +++++++----------
 .../components/post/menu/buttons/show-more.gjs  |  2 +-
 2 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/app/assets/javascripts/discourse/app/components/post/menu.gjs b/app/assets/javascripts/discourse/app/components/post/menu.gjs
index ed70c9cc0f2..44883fd886d 100644
--- a/app/assets/javascripts/discourse/app/components/post/menu.gjs
+++ b/app/assets/javascripts/discourse/app/components/post/menu.gjs
@@ -3,7 +3,6 @@ import { cached, tracked } from "@glimmer/tracking";
 import { hash } from "@ember/helper";
 import { action } from "@ember/object";
 import { getOwner } from "@ember/owner";
-import didInsert from "@ember/render-modifiers/modifiers/did-insert";
 import { service } from "@ember/service";
 import { isEmpty, isPresent } from "@ember/utils";
 import { and, eq } from "truth-helpers";
@@ -396,11 +395,6 @@ export default class PostMenu extends Component {
     return items;
   }
 
-  @action
-  expandIfOnlyOneHiddenButton() {
-    this.collapsed = this.renderableCollapsedButtons.length > 1;
-  }
-
   @cached
   get renderableCollapsedButtons() {
     return this.availableCollapsedButtons.filter((button) =>
@@ -410,9 +404,13 @@ export default class PostMenu extends Component {
 
   @cached
   get visibleButtons() {
-    const nonCollapsed = this.availableButtons.filter((button) => {
-      return !this.availableCollapsedButtons.includes(button);
-    });
+    let nonCollapsed = this.availableButtons;
+
+    if (this.renderableCollapsedButtons.length > 1) {
+      nonCollapsed = nonCollapsed.filter((button) => {
+        return !this.renderableCollapsedButtons.includes(button);
+      });
+    }
 
     return DAG.from(
       nonCollapsed.map((button) => [button.key, button, button.position]),
@@ -609,7 +607,6 @@ export default class PostMenu extends Component {
             "replies-button-visible"
           )
         }}
-        {{didInsert this.expandIfOnlyOneHiddenButton}}
       >
         {{! do not include PluginOutlets here, use the PostMenu DAG API instead }}
         {{#each this.extraControls key="key" as |extraControl|}}
diff --git a/app/assets/javascripts/discourse/app/components/post/menu/buttons/show-more.gjs b/app/assets/javascripts/discourse/app/components/post/menu/buttons/show-more.gjs
index d4aaa78c650..0fb6c4476e6 100644
--- a/app/assets/javascripts/discourse/app/components/post/menu/buttons/show-more.gjs
+++ b/app/assets/javascripts/discourse/app/components/post/menu/buttons/show-more.gjs
@@ -3,7 +3,7 @@ import DButton from "discourse/components/d-button";
 
 export default class PostMenuShowMoreButton extends Component {
   static shouldRender(args) {
-    return args.state.collapsedButtons.length && args.state.collapsed;
+    return args.state.collapsedButtons.length > 1 && args.state.collapsed;
   }
 
   <template>