[libcxx-commits] [libcxx] [libc++][format] Don't leave the output buffer full after a bulk write (PR #226791)

[A. Jiang via libcxx-commits]

https://github.com/frederick-vs-ja approved this pull request.

LGTM. I think we can merge this after CI becomes green, except for Test tools which is recently broken.

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> The overflow is on the stack and has been there since LLVM 20, so this should go into 23.x as well.

I dropped this from the PR description. Please double-check my changes.

I'd like to backport this to LLVM 23, but we usually don't talk about backport to old releases in commit messages.

https://github.com/llvm/llvm-project/pull/226791