From f6279181bb0a919b8547333a62704495213bfbc7 Mon Sep 17 00:00:00 2001
From: Joe Bryan <joemfb@gmail.com>
Date: Tue, 29 Sep 2020 12:36:13 -0700
Subject: [PATCH] u3: adds debug assertion for atom-allocation internal
 invariant

---
 pkg/urbit/noun/imprison.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/pkg/urbit/noun/imprison.c b/pkg/urbit/noun/imprison.c
index c3630ce30..71d530e6d 100644
--- a/pkg/urbit/noun/imprison.c
+++ b/pkg/urbit/noun/imprison.c
@@ -33,6 +33,10 @@ _ci_slab_init(u3i_slab* sab_u, c3_w len_w)
   vat_u->mug_w = 0;
   vat_u->len_w = len_w;
 
+#ifdef U3_MEMORY_DEBUG
+  c3_assert( len_w );
+#endif
+
   sab_u->_._vat_u = vat_u;
   sab_u->buf_w    = vat_u->buf_w;
   sab_u->len_w    = len_w;