fix for operator< on reverse_keyt in miniBDD, fixing segfault in ebmc

Author: Daniel Kroening

src/solvers/miniBDD/miniBDD.cpp

@@ -463,14 +463,20 @@ mini_bddt mini_bdd_mgrt::mk(
 }
 
 bool mini_bdd_mgrt::reverse_keyt::operator<(
-  const mini_bdd_mgrt::reverse_keyt &other) const
+  const mini_bdd_mgrt::reverse_keyt &y) const
 {
-  if(var<other.var || low<other.low)
+  const reverse_keyt &x=*this;
+
+  if(x.var<y.var)
     return true;
-  if(var>other.var || low>other.low)
+  else if(x.var>y.var)
     return false;
-
-  return high<other.high;
+  else if(x.low<y.low)
+    return true;
+  else if(x.low>y.low)
+    return false;
+  else
+    return x.high<y.high;
 }
 
 void mini_bdd_mgrt::DumpTable(std::ostream &out) const

src/solvers/miniBDD/miniBDD.h

@@ -124,7 +124,7 @@ class mini_bdd_mgrt
     reverse_keyt(
       unsigned _var, const mini_bddt &_low, const mini_bddt &_high);
 
-    bool operator<(const reverse_keyt &other) const;
+    bool operator<(const reverse_keyt &) const;
   };
 
   typedef std::map<reverse_keyt, mini_bdd_nodet *> reverse_mapt;