Re: assertion "p >= path" failed

[Tim Adye <T dot J dot Adye at rl dot ac dot uk>]

Hi Ken,

On 31/10/2019 18:19, Ken Brown wrote:
> [Please don't top-post on this list.  Thanks.]
>
> On 10/30/2019 7:56 PM, Tim Adye wrote:
> > I'm afraid I get a very similar error with 3.1.0-0.7:
> >
> > assertion "p >= path" failed: file
> > "/home/kbrown/src/cygpackages/cygwin/cygwin-3.1.0-0.7.x86_64/src/newlib-cygwin/winsup/cygwin/path.cc",
> > line 2906, function: int symlink_info::check(char*, const suffix_info*,
> > fs_info&, path_conv_handle&)
> OK, so your issue is different from the one that was fixed.
>
> > Again following resume from hibernation after going offline with the offline
> > files as HOME (H:\).
> I'm not familiar with offline files, so it would help if you would explain this
> in complete detail.

Offline Files is a feature of Sync Center that makes network files 
available to a user, even if the network connection to the server is 
unavailable. Windows keeps a copy of files stored on the network on the 
local computer. This allows users to work with them even when they are 
not connected to the network or a server is unavailable. The next time 
the user connects to the network or the server is available, their 
offline files on your computer will automatically sync to the network 
files on the server.

I have it set up to keep a local copy of a mapped network drive that 
holds my files (Cygwin $HOME). As I understand it (eg. explained in 
https://docs.microsoft.com/en-us/windows-server/storage/folder-redirection/folder-redirection-rup-overview), 
when the system goes offline, Windows uses the "Folder Redirection" 
feature to redirect access to the client-side cache, C:\Windows\CSC.

I guess Cygwin can choke on this redirected path.
> It would also help if you could capture the assertion failure in a debugger.  Do
> you know how to use gdb?  If so, I would suggest attaching gdb to bash before
> hibernating, and putting a breakpoint at symlink_info::check.  Assuming that gdb
> is still usable after you resume from hibernation, we ought to be able to find
> the cause of the assertion failure.

I will try this, but it will be tricky, because I don't get the 
assertion every time I go offline / hibernate. I'll see if I can work 
out how to provoke the bug reliably. I don't remember the situation from 
every time it's happened, but I think perhaps it can happen if there is 
a bash window open at the time. bash still works, but it can't run 
anything else, nor can I start any new processes. If so, your test might 
be possible, but might not see the symptom, since the problem seems to 
be in processes started by bash. But I'll try.

Thanks,
Tim.
> Ken
>
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