[newlib-cygwin] Cygwin: unlink: allow fallback from POSIX to default method

[Corinna Vinschen <corinna@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=9fa22dba558f5e3efd0bb719049491edcd7b5e0b

commit 9fa22dba558f5e3efd0bb719049491edcd7b5e0b
Author: Corinna Vinschen <corinna@vinschen.de>
Date:   Wed Feb 6 21:17:35 2019 +0100

    Cygwin: unlink: allow fallback from POSIX to default method
    
    Trying to delete in-use executables and DLLs using
    FILE_DISPOSITION_POSIX_SEMANTICS returns STATUS_CANNOT_DELETE.
    Fall back to the former method if that error occurs to allow
    unlinking these files.
    
    Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

Diff:
---
 winsup/cygwin/syscalls.cc | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc
index 62b9638..593c2a4 100644
--- a/winsup/cygwin/syscalls.cc
+++ b/winsup/cygwin/syscalls.cc
@@ -733,7 +733,11 @@ unlink_nt (path_conv &pc)
       if (pc.file_attributes () & FILE_ATTRIBUTE_READONLY)
 	NtSetAttributesFile (fh, pc.file_attributes ());
       NtClose (fh);
-      goto out;
+      /* Trying to delete in-use executables and DLLs using
+         FILE_DISPOSITION_POSIX_SEMANTICS returns STATUS_CANNOT_DELETE.
+	 Fall back to the default method. */
+      if (status != STATUS_CANNOT_DELETE)
+	goto out;
     }
 
   /* If the R/O attribute is set, we have to open the file with