The Cart Blog

Zen Cart Big Chooser Bug Detected

A bug has been detected in all versions of my Zen Cart Big Chooser extension.

The issue was as follows:

• For set_constraint() parameters with multiple required purchases, passing was based on whether the final required quantity passed. So if you used

  $this->set_constraint(CAT, 3, 6, CAT, 2, 5);

  and you had 5 category 2 items but less than 6 category 3 items, the constraint would be considered passed.   (Note: If your set_constraint() parameters have only one required purchase, you are not affected by this bug.)

• For set_choice_constraint() parameters, if you had multiple instances of  set_choice_constraint, passing was based on whether the last one passed. So if you had

  $this->set_choice_constraint(6, CAT, 2);
  $this->set_choice_constraint(6, CAT, 3);

  and you did not have 6 category 2 items but you did have 6 category 3 items, the constraint would be considered passed. (Note: If your choice constraints are consolidated into one single set_choice_constraint parameter, you are not affected by this bug.)

This is the resolution. Edit the file includes/modules/order_total/ot_big_chooser.php, and in the function calculate_deductions() find this block of code:

// If there's a constraint list, make sure the product is in it.

if (sizeof($rule->constraintlist) > 0) {

     $pass = false;

     foreach ($rule->constraintlist as $constraint) {

        $pass = $this->check_cart_constraint($products, $constraint);

     }

     if (!$pass) continue;

}

// If there's a choice constraint list, make sure it's covered.

if (sizeof($rule->choice_constraintlist) > 0) {

     $pass = false;

     foreach ($rule->choice_constraintlist as $constraint) {

        $pass = $this->check_cart_choice_constraint($products, $constraint);

     }

     if (!$pass) continue;

}

Replace it with this block of code:

// If there's a constraint list, make sure the product is in it.

if (sizeof($rule->constraintlist) > 0) {

     $pass = false;

     foreach ($rule->constraintlist as $constraint) {

        $pass = $this->check_cart_constraint($products, $constraint);

        if (!$pass) break;

     }

     if (!$pass) continue;

}

// If there's a choice constraint list, make sure it's covered.

if (sizeof($rule->choice_constraintlist) > 0) {

     $pass = false;

     foreach ($rule->choice_constraintlist as $constraint) {

        $pass = $this->check_cart_choice_constraint($products, $constraint);

        if (!$pass) break;

     }

     if (!$pass) continue;

}

This bug is fixed in Big Chooser version 1.2.0a.  If you already have Big Chooser, I can send you a fresh copy with this fix (and selection by manufacturer) for just $10.