Add unit test for new behavior

Author: reuk

unit/util/simplify_expr.cpp

@@ -8,6 +8,7 @@
 
 #include <catch.hpp>
 
+#include <java_bytecode/java_types.h>
 #include <util/arith_tools.h>
 #include <util/c_types.h>
 #include <util/config.h>
@@ -59,3 +60,23 @@ TEST_CASE("Simplify const pointer offset")
   REQUIRE(!to_integer(simp, offset_value));
   REQUIRE(offset_value==1234);
 }
+
+TEST_CASE("Simplify Java boolean -> int -> boolean casts")
+{
+  config.set_arch("none");
+
+  const exprt simplified=simplify_expr(
+    typecast_exprt(
+      typecast_exprt(
+        symbol_exprt(
+          "foo",
+          java_boolean_type()),
+        java_int_type()),
+      java_boolean_type()),
+    namespacet(symbol_tablet()));
+
+  REQUIRE(simplified.id()==ID_symbol);
+  REQUIRE(simplified.type()==java_boolean_type());
+  const auto &symbol=to_symbol_expr(simplified);
+  REQUIRE(symbol.get_identifier()=="foo");
+}