A poster scale large enough to make both tile counts saturate at
usize::MAX overflowed when they were multiplied for the 1024-sheet
check: a panic with overflow checks, and a product that wraps to 1
without them, which let the sheet loops run. The headless doc_print
tool accepts any finite positive scale, so a script could reach it.
Multiply with checked_mul and treat an overflow as over the limit, so
the request gets the existing "more than 1024 sheets" error.
Adds tests::huge_posters_are_refused_at_the_sheet_limit, which panics
before this change and passes with and without overflow checks after it.
Marco Arnulfo
2796f3de0d