[newlib-cygwin] Cygwin: console: Prevent NULL pointer access in close().

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=6cde7279a00452ed1ccc0ffc39d9011b016fadb3

commit 6cde7279a00452ed1ccc0ffc39d9011b016fadb3
Author: Takashi Yano via Cygwin-patches <cygwin-patches@cygwin.com>
Date:   Mon Feb 22 22:30:17 2021 +0900

    Cygwin: console: Prevent NULL pointer access in close().
    
    - There seems to be a case that shared_console_info is not set yet
      when close() is called. This patch adds guard for such case.

Diff:
---
 winsup/cygwin/fhandler_console.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/winsup/cygwin/fhandler_console.cc b/winsup/cygwin/fhandler_console.cc
index 6ded9eabf..96a8729e8 100644
--- a/winsup/cygwin/fhandler_console.cc
+++ b/winsup/cygwin/fhandler_console.cc
@@ -1393,7 +1393,7 @@ fhandler_console::close ()
 
   release_output_mutex ();
 
-  if (con.owner == myself->pid)
+  if (shared_console_info && con.owner == myself->pid)
     {
       char name[MAX_PATH];
       shared_name (name, CONS_THREAD_SYNC, get_minor ());