markdown: fix scroll sync regressions introduced in #287050#307763
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AshtonYoon wants to merge 1 commit intomicrosoft:mainfrom
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markdown: fix scroll sync regressions introduced in #287050#307763AshtonYoon wants to merge 1 commit intomicrosoft:mainfrom
AshtonYoon wants to merge 1 commit intomicrosoft:mainfrom
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Two regressions from the merge of microsoft#287050: 1. preview.ts: The merge retained `this.#isScrolling = false` inside the early-return guard of `scrollTo()`, which was intentionally removed in the original PR. This resets the timer-based flag on the very first forward-sync call, allowing subsequent editor scroll events to re-trigger forward sync while reverse sync is in progress, causing the editor to jump back up. 2. index.ts: The PR converted `onUpdateView` from a decrement-counter to a timer-based approach but left initialization and resize handlers still using `scrollDisabledCount += 1` without a corresponding timer reset. The old scroll handler decremented the counter naturally; the new handler only returns early. As a result, after page load `scrollDisabledCount` stays at 1 indefinitely, blocking all preview-to-editor sync until the user scrolls the editor once. Fixes: - Remove the erroneous `this.#isScrolling = false` from scrollTo() - Apply the same timer-reset pattern (200ms) to initialization and resize handlers so scrollDisabledCount is always auto-cleared Fixes microsoft#307762
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Fixes #307762
Bug 1: Editor jumps when scrolling the preview (
preview.ts)The merge retained
this.#isScrolling = falseinside the early-return guard ofscrollTo(), which the original PR intentionally removed. This resets the timer on the first call, letting subsequent editor scroll events re-trigger forward sync while reverse sync is still in progress.if (this.#isScrolling) { - this.#isScrolling = false; return; }Bug 2: Preview → editor sync requires editor to be scrolled first (
index.ts)The PR switched
onUpdateViewto a timer-based reset but left initialization and resize handlers still usingscrollDisabledCount += 1with no timer. Since the scroll handler no longer decrements,scrollDisabledCountstays at1after page load and blocks all preview-to-editor sync.Fix: apply the same timer-reset pattern (200ms) to all four remaining increment sites.