[newlib-cygwin] Cygwin: pty: Fix a small bug in is_console_app().

[Takashi Yano]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=249f42d07a447ceb6fe22db5a2570f913cb5b4e5

commit 249f42d07a447ceb6fe22db5a2570f913cb5b4e5
Author: Takashi Yano <takashi.yano@nifty.ne.jp>
Date:   Fri Aug 5 17:53:16 2022 +0900

    Cygwin: pty: Fix a small bug in is_console_app().
    
    - Previsouly, there was potential risk of buffer over run in
      is_console_app(). This patch fixes the issue.

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

diff --git a/winsup/cygwin/spawn.cc b/winsup/cygwin/spawn.cc
index 7de96827c..641f23642 100644
--- a/winsup/cygwin/spawn.cc
+++ b/winsup/cygwin/spawn.cc
@@ -224,7 +224,7 @@ is_console_app (WCHAR *filename)
   ReadFile (h, buf, sizeof (buf), &n, 0);
   CloseHandle (h);
   char *p = (char *) memmem (buf, n, "PE\0\0", 4);
-  if (p && p + id_offset <= buf + n)
+  if (p && p + id_offset < buf + n)
     return p[id_offset] == '\003'; /* 02: GUI, 03: console */
   else
     {