From 25d4807f507274d421966e06cd960d1b50366c5a Mon Sep 17 00:00:00 2001
From: Kris Katterjohn <katterjohn@gmail.com>
Date: Fri, 4 Oct 2019 20:39:37 -0500
Subject: [PATCH] mmapped heaps: fix the file descriptor argument to mmap for
 the BSDs

On the BSDs, the file descriptor passed to mmap when using MAP_ANON
must be -1.  Passing 0 causes mmap to fail.
---
 gc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gc.c b/gc.c
index 8802fbdf..0d938bdd 100644
--- a/gc.c
+++ b/gc.c
@@ -501,7 +501,7 @@ sexp_heap sexp_make_heap (size_t size, size_t max_size, size_t chunk_size) {
   sexp_heap h;
 #if SEXP_USE_MMAP_GC
   h =  mmap(NULL, sexp_heap_pad_size(size), PROT_READ|PROT_WRITE|PROT_EXEC,
-            MAP_ANON|MAP_PRIVATE, 0, 0);
+            MAP_ANON|MAP_PRIVATE, -1, 0);
   if (h == MAP_FAILED) return NULL;
 #else
   h =  sexp_malloc(sexp_heap_pad_size(size));