Re: Fwd: [glennrp/libpng] Undefined behaviour in pngutil.c (#149)
John Bowler <[email protected]>
| Newsgroups | gmane.comp.graphics.png.devel |
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| Message-ID | <CAP7U39-Q-+GOryQQch1nQppTzvgjx0Yhf9WayUpuUbaE_tN13w@mail.gmail.com> |
On Mon, Jan 2, 2017 at 4:40 PM, Glenn Randers-Pehrson <[email protected]> wrote: > This bug report is correct. > Yes, tricky maintainer feature; the 'options' field is entirely internal so can be changed in maintenance releases. Doing this does, I think, work: unsigned option : PNG_OPTION_LAST * 2; (I didn't check the current code, but something along those lines will work.) That means the compiler will barf if PNG_OPTION_LAST ever gets set to something out of range for the base type and therefore guarantees that neither the undefined behavior nor the current result (the new option is always off) happens. John Bowler ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ png-mng-implement mailing list png-mng-implement-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org https://lists.sourceforge.net/lists/listinfo/png-mng-implement