Streamdown Files

Minor Changes

• fdd1351: Rework code-region detection and double-underscore counting.

A shared single-pass scanner now classifies fences and inline code spans, replacing the per-character rescans that made healing quadratic on delimiter-heavy input. Fence and span detection follows CommonMark, so ~~~ fences, fences inside block quotes and list items, CRLF line endings, and multi-backtick spans are all recognized, and content inside code is never healed as prose.

Double underscores are counted per maximal run with flanking rules, so identifiers containing __ (like snake__case) no longer invent or swallow emphasis closers.

Healing is now idempotent. Healed output re-heals to itself, and text-only link mode resolves every unmatched bracket in one call.

Patch Changes

• cf0ac1c: Stop the incomplete-HTML-tag handler from truncating math expressions.

handleIncompleteHtmlTag guarded against code blocks but not math, so an ordinary comparison inside math — $$ I = \sum_{j<k} p_j $$ — matched the incomplete-tag pattern and deleted everything from the < to the end of the string. The trailing $$ was then auto-closed by the katex handler, so KaTeX rendered a parse error and the rest of the message never reached the DOM.

The handler now skips candidates inside math blocks ($, $$, \(, \[), matching the guard the emphasis handlers already had. Because the pattern is leftmost-matching, it also walks forward to later candidates instead of bailing out, so a genuine incomplete tag after a math expression is still stripped.

• e0ce123: Incomplete images during streaming now render a loading placeholder instead of being removed entirely. Incomplete images (e.g. ![alt](https://exampl) are replaced with ![alt](streamdown:incomplete-image) by remend, and the streamdown ImageComponent renders an animated skeleton for this special URL. This mirrors the existing behavior for incomplete links (streamdown:incomplete-link). The streamdown protocol is allowlisted for img[src] in the default sanitize schema so the sentinel survives rehype-sanitize + rehype-harden.