From 4a5630bfcefc728b57cd8fcc5efc4923e786fe17 Mon Sep 17 00:00:00 2001
From: Mohamed Boudra <boudra.moha@gmail.com>
Date: Wed, 15 Jul 2026 12:04:53 +0200
Subject: [PATCH] fix(app): stop composer height flicker

Native scrollbar appearance changed the textarea's usable width, feeding alternating measurements back into the composer height mirror. Reserve the gutter so wrapping and height remain stable.
---
 packages/app/src/composer/input/input.tsx                   | 2 ++
 packages/app/src/styles/install-web-scrollbar-styles.web.ts | 4 ++++
 2 files changed, 6 insertions(+)

diff --git a/packages/app/src/composer/input/input.tsx b/packages/app/src/composer/input/input.tsx
index b35a2811d..6d57619ea 100644
--- a/packages/app/src/composer/input/input.tsx
+++ b/packages/app/src/composer/input/input.tsx
@@ -74,6 +74,7 @@ import {
 } from "./state";
 
 const DEFAULT_SEND_KEYS: ShortcutKey[][] = [["Enter"]];
+const COMPOSER_INPUT_DATASET = { composerInput: "" } as const;
 
 export interface AttachmentMenuItem {
   id: string;
@@ -1807,6 +1808,7 @@ export const MessageInput = forwardRef<MessageInputRef, MessageInputProps>(
           <View style={styles.textInputScrollWrapper}>
             <ThemedTextInput
               ref={textInputRef}
+              dataSet={COMPOSER_INPUT_DATASET}
               value={value}
               onChangeText={handleInputChange}
               placeholder={placeholder ?? t("composer.placeholders.fallback")}
diff --git a/packages/app/src/styles/install-web-scrollbar-styles.web.ts b/packages/app/src/styles/install-web-scrollbar-styles.web.ts
index 18652c7f4..db11698cd 100644
--- a/packages/app/src/styles/install-web-scrollbar-styles.web.ts
+++ b/packages/app/src/styles/install-web-scrollbar-styles.web.ts
@@ -19,6 +19,10 @@ export function installWebScrollbarStyles(): () => void {
   scrollbar-width: ${WEB_SCROLLBAR_WIDTH};
 }
 
+[data-composer-input] {
+  scrollbar-gutter: stable;
+}
+
 *::-webkit-scrollbar {
   width: ${WEB_SCROLLBAR_SIZE_PX}px;
   height: ${WEB_SCROLLBAR_SIZE_PX}px;