Hello John,
21.01.2026 12:05, John Naylor wrote:
As for the rest of the proposed fixes, most seem okay, but I have some nits:
Thank you for spending time on this!
I agree with all of your changes (except for one noted below) -- didn't
mean to propose committable changes, just wanted to show the fixes that
allowed check-world to pass.
heaptoast.c
memcpy(VARDATA(result) +
- (curchunk * TOAST_MAX_CHUNK_SIZE - sliceoffset) + chcpystrt,
+ (int)(curchunk * TOAST_MAX_CHUNK_SIZE - sliceoffset) + chcpystrt,
Not sure about this one. It would be better if we reversing the
operands allowed us to avoid overflow in the first place:
- (curchunk * TOAST_MAX_CHUNK_SIZE - sliceoffset) + chcpystrt,
+ chcpystrt + (curchunk * TOAST_MAX_CHUNK_SIZE - sliceoffset)
Does that silence the warning?
Unfortunately, no -- I still got:
heaptoast.c:771:17: runtime error: addition of unsigned offset to
0x78120673fac6 overflowed to 0x78120673fa04
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior heaptoast.c:771:17
Best regards,
Alexander
