Re: [PATCH] Cygwin: path: Fix path conversion of virtual drive.

[Takashi Yano <takashi.yano@nifty.ne.jp>]

On Thu, 9 Dec 2021 11:08:46 +0100
Corinna Vinschen wrote:
> On Dec  9 17:17, Takashi Yano wrote:
> > +		      if (!QueryDosDeviceW (drive, remote, MAX_PATH))
> > +			goto file_not_symlink; /* fallback */
> > +
> > +		      int remlen = wcslen (remote);
> 
> QueryDosDeviceW returns the string followed by two \0 chars, and that's
> reflected by its return value.  You could skip the wcslen call:
> 
>                       int remlen;
> 		      remlen = QueryDosDeviceW (drive, remote, MAX_PATH);
> 		      if (!remlen)
> 		      	goto file_not_symlink;
> 		      remlen -= 2;
> 
> 
> > +		      if (remote[remlen - 1] == L'\\')
> > +			remlen--;
> > +		      WCHAR *p;
> > +		      if (wcsstr (remote, L"\\??\\UNC\\") == remote)
> 
> That should be wcsncmp.  The subst'ed UNC path always begins with that
> string.  Alternatively:
> 
> 		      UNICODE_STRING rpath;
> 		      RtlInitCountedUnicodeString (&rpath, remote,
> 						   remlen * sizeof (WCHAR));
> 		      if (RtlEqualUnicodePathPrefix (&rpath, &ro_u_uncp, TRUE))
> 
> 
> > +			remlen -= 6;
> > +		      else if ((p = wcschr (remote, L';') + 1)
> 
> This expression is always true, even if wcschr returns a NULL pointer.
> 
> > +			       && wcsstr (p, drive) == p
> 
>                                && wcsncmp (p, drive, 2) == 2?
> 
> Alternatively just skip the additional drive letter check and move
> the pointer immediately forward to the next backslash:

Thanks for checking and advice. I'll submit v2 patch shortly.

-- 
Takashi Yano <takashi.yano@nifty.ne.jp>