[Bug]: Horizontal trackpad scrolling in the diff panel triggers back/forward navigation #28159

Before submitting

• I searched existing issues and did not find a duplicate of this specific diff-panel bug report.
• I included enough detail to reproduce or investigate the problem.

Area

apps/desktop — diff panel and back/forward gesture navigation

What happened

When a diff contains a very long line, the diff panel shows a horizontal scrollbar. Using a trackpad to scroll left or right sometimes triggers the application's back/forward navigation instead of scrolling the diff. This unexpectedly navigates away from the current view and interrupts reviewing the changes.

Steps to reproduce

1. Open a diff containing a line wide enough to require horizontal scrolling.
2. Place the pointer over the diff panel and interact with it.
3. Use a trackpad to scroll horizontally left and right.
4. Repeat the gesture; intermittently, the application navigates backward or forward instead of keeping the interaction within the diff.

Expected behavior

Horizontal scrolling while interacting with the diff panel should scroll its contents without triggering application back/forward navigation. The same protection should apply to other scrollable panels: a content-scrolling gesture should not unexpectedly navigate away, including when the content reaches a scroll boundary.

Actual behavior

The horizontal trackpad gesture sometimes triggers application back/forward navigation while the user is trying to scroll the diff.

Impact

Minor bug or occasional failure — interrupts diff review by unexpectedly changing the current view.

Version or commit

Not provided.

Environment

macOS; trackpad input. Exact macOS and T3 Code versions were not provided.

Screenshots, recordings, or supporting files

A screen recording of the reported behavior is available, but could not be attached during submission because the CLI upload requires repository write access.

Related issue

#28023 requested a setting to disable swipe back/forward navigation and is closed. This report concerns preventing content-scrolling gestures from triggering navigation while interacting with the diff or another scrollable panel.

Workaround

No workaround provided.