Hello Yoann,
Thank you for your review and for pointing this out.
Ref: https://lore.kernel.org/all/DJJ1VQ85GDU1.2F6PDWUSCET4Z@smile.fr/

I have submitted the rebased v2 patch here:
[scarthgap][PATCH v2] libpng: Fix CVE-2026-34757

Thanks and Regards,
Sudhir