> The problem is that autossh is freeing the return value of > gethostbyname(). I can't find any reference which says that is a > acceptable thing to do. It certainly screws up cygwin, and I can't > think of any way to avoid having it screw up cygwin. Maybe it won't > screw up other systems since they may not malloc the return value of > gethostbyname. I dunno.
OK. (hangs head) I have to take the blame for this, because as it happens I contributed that bit of code. Forgive my simplicity on this point, but it seemed like good memory heigene-- free up the memory that gethostbyname() allocated, once I was done with it. Looking back now at the man page for gethostbyname() (in Linux, there's no Cygwin man page AFAIK), it seems unclear on this point: the NOTES section says "The functions gethostbyname() and gethostbyaddr() *may* return pointers to static data, which may be overwritten by later calls." (emphasis added) This may have been a dumb mistake, or not. Obviously if the memory is static, I shouldn't free() it, but the docs are unclear about whether it is or not. Should I infer that I should not free() memory allocated by a function that I call unless the man page specifically says to? Or just that it's best not to free() it if it might be static? This seems like a complicated issue and any pointers for this journeyman network programmer would be welcome. Probably OT for this list, though. > I haven't run an exhaustive test, but the patch below seems to fix this > problem. Confirmed, it fixes my crash here with cygwin1.dll snapshot of 2005-Mar- 11. > Could the autossh maintainer look into getting this applied upstream? Done. I'll release a new version shortly. Andrew. -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
