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Re: cygwin_create_path causes null pointer crashes


Am 13.12.2016 um 12:56 schrieb Corinna Vinschen:
On Dec 12 20:28, Thomas Wolff wrote:
Hi Corinna,

Am 11.12.2016 um 12:08 schrieb Corinna Vinschen:
Hi Thomas,

On Dec 10 03:03, Thomas Wolff wrote:
cygwin_create_path is supposed to call malloc itself,
however, it occasionally returns with null and errno == ENOSPC,
if it's provided with a network path, e.g.
cygwin_create_path(CCP_POSIX_TO_WIN_W, "/cygdrive/s/.config/mintty")
returns null in ~ 3 of 1000 cases, where /cygdrive/s exists but
/cygdrive/s/.config does not
Did you try to debug and fix the issue?  This is the developer's mailing
list after all...
I can contribute some initial analysis:
Cloning cygwin_create_path from cygwin/path.cc with these essentials:
   ssize_t size = cygwin_conv_path (what, from, NULL, 0);
   // checking size, calling malloc
   if (cygwin_conv_path (what, from, to, size) == -1)
Cloning?  Why didn't you just debug with GDB and/or strace?
Well, one reason is that I had to manipulate the value of size between the two calls ...

...
A simple strace shows that there's a really ugly problem with network shares:

...
Anyway, we can't fix Windows, but we can workaround its problems, which
is what Cygwin does, so I applied a patch.
Great, this works, thanks.

Thomas


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