[newlib-cygwin] Fix invalid acl_entry_t on 32-bit Cygwin

[Corinna Vinschen <corinna@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=acfc63b0cf0df472a8e17df1bf5a2c8284e28833

commit acfc63b0cf0df472a8e17df1bf5a2c8284e28833
Author: David Allsopp <david.allsopp@metastack.com>
Date:   Thu Jul 9 20:17:03 2020 +0100

    Fix invalid acl_entry_t on 32-bit Cygwin
    
    If the acl_t struct was at or above 0x80000000 then the pointer was
    sign-extended to 0xffff_ffff_8000_0000 and so the index was lost.
    
    Signed-off-by: David Allsopp <david.allsopp@metastack.com>

Diff:
---
 winsup/cygwin/release/3.1.7  | 4 ++++
 winsup/cygwin/sec_posixacl.h | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/winsup/cygwin/release/3.1.7 b/winsup/cygwin/release/3.1.7
new file mode 100644
index 000000000..6ce316fc4
--- /dev/null
+++ b/winsup/cygwin/release/3.1.7
@@ -0,0 +1,4 @@
+Bug Fixes:
+----------
+
+- Fix acl_get_* functions in 32-bit Cygwin (pointer sign extension)
diff --git a/winsup/cygwin/sec_posixacl.h b/winsup/cygwin/sec_posixacl.h
index a3790a52b..0f9e7bde3 100644
--- a/winsup/cygwin/sec_posixacl.h
+++ b/winsup/cygwin/sec_posixacl.h
@@ -34,7 +34,7 @@ struct __acl_t
 inline acl_entry_t
 __to_entry (acl_t acl, uint16_t idx)
 {
-  return ((uint64_t) idx << 48) | (uint64_t) acl;
+  return ((uint64_t) idx << 48) | (uint64_t) ((uintptr_t) acl);
 }
 #define __to_permset(a,i)	((acl_permset_t)__to_entry((a),(i)))