From 2d4fc08f2b4f7a594764ebcd355bc852d17a1b49 Mon Sep 17 00:00:00 2001
From: Henry Heino <46334387+personalizedrefrigerator@users.noreply.github.com>
Date: Fri, 2 Feb 2024 10:50:56 -0800
Subject: [PATCH] Desktop: Fixes #9629: Fix horizontal touchpad scrolling of
 code blocks (#9815)

---
 packages/app-desktop/gui/note-viewer/index.html | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/packages/app-desktop/gui/note-viewer/index.html b/packages/app-desktop/gui/note-viewer/index.html
index 39aa026da..3dd6b2bb2 100644
--- a/packages/app-desktop/gui/note-viewer/index.html
+++ b/packages/app-desktop/gui/note-viewer/index.html
@@ -594,12 +594,20 @@
 			// calculate by yourself by accumulating wheel events.
 			// https://github.com/laurent22/joplin/pull/5496
 			// When the Electron/Chromium bug is fixed, remove this listener.
+			//
+			// 2024-02-01: The bug seems to be fixed, remove the above when we're not in
+			//             feature-freeze.
 
 			// If scrollTop ever has a fraction part, zoomFactor is not 1.
 			if (zoomFactorIsNotOne || !Number.isInteger(contentElement.scrollTop)) {
 				zoomFactorIsNotOne = true;
-				customScroll(e, true);
-				e.preventDefault();
+
+				// The custom scroll logic breaks horizontal scroll in child DOM nodes
+				// (e.g. scrollable code blocks). Disable it:
+				if (e.deltaY !== 0) {
+					customScroll(e, true);
+					e.preventDefault();
+				}
 			}
 		}));