Check whether this_bal actually finds a matching commodity value, otherwise

it's a divide by zero.

journal.cc

@@ -161,6 +161,7 @@ bool entry_base_t::finalize()
     if (this_bal == other_bal)
       other_bal++;
 
+    if (this_bal != ((balance_t *) balance.data)->amounts.end()) {
       amount_t per_unit_cost =
 	amount_t((*other_bal).second / (*this_bal).second).unround();
 
@@ -185,6 +186,7 @@ bool entry_base_t::finalize()
 	balance += *(*x)->cost;
       }
     }
+  }
 
   // Walk through each of the transactions, fixing up any that we
   // can, and performing any on-the-fly calculations.