readQuoted treated \X as an escape for any X, so a single literal
backslash in any quoted attribute value was silently dropped
(data-path="C:\Users" parsed as C:Users) and a doubled backslash
collapsed to one. Only the delimiter and the backslash itself are
escapes now; every other backslash is a literal character.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>