2718 - stop crashing on unknown space

I'm going to stop wasting precious first-line characters on 'bugfix:'.
It's going to be all bugfixes for a while I think.

1 files changed, 1 insertions, 0 deletions

diff --git a/043space.cc b/043space.cc
index 5bf7b1a4..9ca747b7 100644
--- a/043space.cc
+++ b/043space.cc
@@ -69,6 +69,7 @@ long long int space_base(const reagent& x) {
 }
 
 long long int address(long long int offset, long long int base) {
+  assert(offset >= 0);
   if (base == 0) return offset;  // raw
   long long int size = get_or_insert(Memory, base);
   if (offset >= size) {