fix: use cached row pins for WASM viewport rendering#133
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Replace per-row pages.pin(.active) calls in renderStateGetViewport with cached row pins from RenderState.row_data, matching how the native renderer reads cell data. This avoids inconsistent top-left resolution when the viewport spans multiple pages. Also fixes scrollback_limit to properly convert line counts to bytes (matching Terminal.init's expected units) and adds Page imports needed for the bytes-per-line calculation. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
This was referenced Mar 13, 2026
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) Ports fixes for upstream issues coder#138 and coder#139: Issue coder#139 (viewport corruption when viewport spans multiple pages): - renderStateGetViewport: replace per-row pages.pin(.active) calls with cached row pins from RenderState.row_data, matching the native renderer. Independent per-row pin resolution produced inconsistent results across page boundaries. - terminal_new_with_config: convert scrollback_limit from line count to bytes using page layout calculation (Terminal.init expects bytes, not lines). This makes the page-spanning condition much less frequent. Issue coder#138 (stale cell data visible after scroll with default cursor style): - cursorDownScroll in Screen.zig: make row clearing unconditional. The old check `if (bg_color != .none)` skipped clearing when cursor style was default (after ESC[0m), leaving stale cells from reused page memory visible on empty lines. Inspired by: coder#133 Inspired by: coder#134 Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>
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Summary
pages.pin(.active)calls inrenderStateGetViewportwith cached row pins fromRenderState.row_data, matching how the native renderer reads cell datascrollback_limitto properly convert line counts to bytes (matchingTerminal.init's expected units)Pageimports needed for the bytes-per-line calculationThe per-row approach independently resolved the viewport top-left position for every row, which could produce inconsistent results when the viewport spanned multiple pages. Using the cached pins (built during
update()) matches the native renderer's approach and avoids this class of issues.Test plan
bun test lib/iris-repro-final.test.ts— scrollback and viewport regression tests passbun test lib/iris-repro-fix-verify.test.ts— scrollback drop verification passesbun test— full suite passes🤖 Generated with Claude Code