[RZIL] Fix reachable endless loop. (#3940)

* Fix reachable endless loop.

If rz_il_evaluate_effect() fails to execute it returns false and expects
that the execution is terminated.
Because res was never checked for false, repeat kept going endlessly
in such a case.

* Add unit test for endless loop in case of malformed effect.

librz/il/theory_effect.c

@@ -109,7 +109,10 @@ bool rz_il_handler_repeat(RzILVM *vm, RzILOpEffect *op) {
 		if (!condition->b) {
 			break;
 		}
-		res = res && rz_il_evaluate_effect(vm, op_repeat->data_eff);
+		if (!rz_il_evaluate_effect(vm, op_repeat->data_eff)) {
+			res = false;
+			break;
+		}
 		rz_il_bool_free(condition);
 	}
 	rz_il_bool_free(condition);

test/unit/test_il_validate.c

@@ -1086,6 +1086,18 @@ static bool test_il_validate_effect_repeat() {
 	mu_assert_streq_free(report, "Body operand of repeat op does not only perform data effects.", "report");
 	rz_il_op_effect_free(op);
 
+	//////////////////////////
+	// malformed effect handling
+
+	op = rz_il_op_new_seqn(2,
+		rz_il_op_new_set("x", true, rz_il_op_new_bitv_from_ut64(32, 1)),
+		rz_il_op_new_repeat(rz_il_op_new_non_zero(rz_il_op_new_var("x", RZ_IL_VAR_KIND_LOCAL)),
+			rz_il_op_new_set("x", true, rz_il_op_new_sub(rz_il_op_new_var("x", RZ_IL_VAR_KIND_LOCAL), rz_il_op_new_b1()))));
+	val = rz_il_validate_effect(op, ctx, &local_var_sorts, &t, &report);
+	mu_assert_false(val, "invalid");
+	mu_assert_streq_free(report, "Right operand of sub op is not a bitvector.", "report");
+	rz_il_op_effect_free(op);
+
 	rz_il_validate_global_context_free(ctx);
 	mu_end;
 }