On Sep 14 20:59, Corinna Vinschen wrote: > On Sep 14 17:39, John Carey wrote: > > On Sep 14 01:12, Corinna Vinschen wrote: > > > Hmm, I'm still wondering. In theory we don't have to replace the > > > directory name. We just have to InterlockedExchange the handle, since > > > we only need to replace the original handle which does not allow > > > sharing-for-delete with our own handle which does. > > > > > > All other border cases (virtual dir, directory with restricted rights) > > > can be rightfully handled by setting the Win32 CWD to \\?\PIPE\ again. > > > > > > That's at least worth a try, isn't it? > > > > Oh, I had thought that you wanted it for long paths > > and directories with restricted rights, too. > > That would be nice, but to me it looks like the Win32 API is just too > restricted for that, so that it won't make much sense. The native API > can't make any assumption that it would work in such a scenario. > > Most Win32 calls will still not work in a restricted rights CWD, because > they neglect to set the FILE_OPEN_FOR_BACKUP_INTENT flag. And most Apps > don't set the FILE_FLAG_BACKUP_SEMANTICS flag incalls to CreateFile. > > As for long paths, there's some chance that the internal calls creating > an absolute path from a relative path fail or crash if the CWD is longer > than MAX_PATH. What MSDN has to say about the maximum path length of > relative paths(*) is not very promising, at least. Also, even if > Vista++ allows to create VistaCwd entries with a longer path, this would > probably break starting native child processes due to the MAX_PATH > restriction for the CWD in calls to CreateProcess. > > > There's one other issue: the new directory will limit deletion > > very briefly, until replaced. I don't know if that will bother > > people as much as the current situation. > > True. Implementing a full replacement for SetCurrentDirectory as in > your PoC is still an option. However, I can't do that anymore since > I'm tainted by reading your code. If you would contemplate to sign > a copyright assignment(**), we could create a more thorough solution > with code scanning and all that in the long run. > > In the meantime, I could apply my patch and we can try how well it > works, hacked as it is. > > > Corinna > > > (*) http://msdn.microsoft.com/en-us/library/aa365247%28VS.85%29.aspx
Sorry, I forgot the URL: (**) http://cygwin.com/contrib.html, the "Before you get started" section. Corinna -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Project Co-Leader cygwin AT cygwin DOT com Red Hat -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
