fix: use split('\n') instead of splitlines() in blockquote renderer#581
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gaoflow wants to merge 1 commit into
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fix: use split('\n') instead of splitlines() in blockquote renderer#581gaoflow wants to merge 1 commit into
gaoflow wants to merge 1 commit into
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The blockquote renderer used str.splitlines() to split rendered text
into lines, but splitlines() treats Unicode line separators (form feed
\x0c, vertical tab \x0b, file/group/record separators, NEL \x85,
line/paragraph separator) as line breaks.
CommonMark only recognizes \n, \r\n, and \r as line endings. Other
renderers (paragraph, list_item) correctly use split('\n').
When blockquote content contained Unicode whitespace like form feed,
the renderer would split on it and prepend spurious '> ' markers,
creating semantically different output on the first format pass. The
second pass then normalized this, breaking idempotence.
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Blockquote rendering in mdformat is non-idempotent when the content
contains Unicode whitespace characters like form feed (
\x0c),vertical tab (
\x0b), or Unicode line separators.f(f(x)) != f(x)— the first format pass produces semanticallydifferent output from the input. The second pass normalizes it.
Minimal reproduction:
Root cause:
blockquote()in_context.pyusestext.splitlines()which splits on Unicode line separators thatCommonMark does not recognize. The other renderers (
paragraph,list_item) correctly usetext.split("\n").Fix (+1/-1):
text.splitlines()→text.split("\n")— bringsblockquote in line with paragraph and list_item.
4282/4282 tests pass (5 skipped pre-existing).
211/211 idempotence fuzz tests pass.
This pull request was prepared with the assistance of AI, under my
direction and review.