←back to thread

How a 20 year old bug in GTA San Andreas surfaced in Windows 11 24H2

(cookieplmonster.github.io)
1371 points yett | 4 comments | 23 Apr 25 14:00 UTC | HN request time: 0.615s | source
Show context
amenghra ◴[23 Apr 25 18:08 UTC] No.43774928[source]▶
IMHO, if something isn’t part of the contract, it should be randomized. Eg if iteration order of maps isn’t guaranteed in your language, then your language should go out of its way to randomize it. Otherwise, you end up with brittle code: code that works fine until it doesn’t.
replies(11): >>43774993 #>>43775199 #>>43775210 #>>43775344 #>>43775361 #>>43775510 #>>43775759 #>>43776084 #>>43776311 #>>43776598 #>>43778608 #
willcipriano ◴[23 Apr 25 18:59 UTC] No.43775510[source]▶
Then you are wasting runtime clock cycles randomizing lists.
replies(3): >>43775920 #>>43776036 #>>43779041 #
1. nayuki ◴[23 Apr 25 19:42 UTC] No.43775920[source]▶
Any sane language would design a list iterator to follow the order of the list. No, the difference is when you're iterating over orderless hash-based sets or maps/dictionaries. Many languages choose to leave the iteration order undefined. I think Python did that up to a point, but afterward they defined dictionaries (but not sets) to be iterated over in the order that keys were added. Also, some languages intentionally randomize the order per program run, to avoid things like users intentionally stuffing hash tables with colliding keys.
replies(2): >>43777295 #>>43780231 #
2. mabster ◴[23 Apr 25 22:21 UTC] No.43777295[source]▶
Best change ever, that. Now it would also be nice if sets were ordered too.
replies(1): >>43778982 #
3. throwaway2037 ◴[24 Apr 25 03:22 UTC] No.43778982[source]▶
I am pretty sure there are trivial impls of sets with guaranteed iteration order in Python that use an underlying ordered map and a dummy value in each entry.
4. masklinn ◴[24 Apr 25 07:55 UTC] No.43780231[source]▶
> Also, some languages intentionally randomize the order per program run, to avoid things like users intentionally stuffing hash tables with colliding keys.

Most modern langages do that as part of hashdos mitigation, Python did that until it switched to a naturally ordered hashmap, then made insertion order part of the spec. Importantly iteration order remains consistent with a process (possibly on a per-hashmap basis).

Notably, Go will randomise the starting point of hashmap iteration on each iteration.