Fix operator precedence in timeline pageSize calculation

[Shehab Sherif (ShehabSherif0)]

Fixes #303257

Bug

In TimelinePane.pageSize, the nullish coalescing operator (??) has lower precedence than division (/), causing renderHeight (pixels) to be used directly as the page size instead of renderHeight / ItemHeight (items).

Current code

pageSize = Math.max(20, Math.floor((this.tree?.renderHeight ?? 0 / ItemHeight) + (this.pageOnScroll ? 1 : -1)));

JavaScript parses this as this.tree?.renderHeight ?? (0 / ItemHeight) because / binds tighter than ??.

When the tree exists (the common case), renderHeight is a pixel value (e.g., 500). Without the division by ItemHeight (22), the computed page size is ~499 instead of the intended ~22. This causes a ~24x over-fetch on every timeline load and "Load more" action.

Fix

Add parentheses to enforce the intended grouping:

pageSize = Math.max(20, Math.floor(((this.tree?.renderHeight ?? 0) / ItemHeight) + (this.pageOnScroll ? 1 : -1)));

Verification

const ItemHeight = 22, renderHeight = 500;

// Buggy:  renderHeight ?? (0 / ItemHeight)  => 500  =>  pageSize = 499
// Fixed:  (renderHeight ?? 0) / ItemHeight   => 22.7 =>  pageSize = 21

When the tree is null/undefined, both produce pageSize = 20 (via Math.max), so the fallback path is unaffected.

[Copilot]

Pull request overview

Fixes an operator-precedence bug in TimelinePane.pageSize that caused pixel renderHeight values to be treated as an item count, leading to significant over-fetching in the Timeline view.

Changes:

• Adds parentheses around the nullish-coalescing expression to ensure renderHeight is divided by ItemHeight before computing the page size.

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