Duplicate Products in Cart although single added

[samir_arora]

hello guys,

I have a weird problem in our magento installation. Sometimes a product is added more than once to the quote although the customer only added it once. The weirdest part is that the "created_at" timestamp is exactly the same in both positions of the quote_item table. and this occurs quite often and we are receiving quite a few complaints from our customers. Any ideas as to how I should go about debugging?

It seems as the wrong positions are added randomly. Sometimes right after the specific product is added to the cart, sometimes if some other product is added. But it really is a kopie each time as the timestamps and buyRequest etc are exactly the same. 

I would realy appreciate any help

Thanx already

ps. I would have liked to insert a screenshot but i cant :/

[kimberelyt]

Hi Samir,

Could you have installed any extensions that are causing this problem? I would try by setting disable local modules in app/etc/local.xml

<disable_local_modules>false</disable_local_modules>

to true

If this rids the problem than you know one of your extensions is causing the problem and you could disable them all individually and then add them back one to one (maybe with the most conspicuous first to narrow it down faster).

[samir_arora]

Hi Kimberley,

first of all thanks for your reply

But the thing is that:

1. there are quite a lot of extensions installed. We are working with this specific installation for the last 3-4 years. So I guess that disabling the modules would break my system completely

2. the phenomenon doesnt occur each time. May be once every 700-800 orders. And we do have some 3000 orders every day. Plus I have not been able to reproduce it on the Dev-Install. But one can see in the order_item and quote_item tables that the position has been copied (the same created_at in quote_item)

3. I even considered if the customers are able to do that by ordering the same product more than once. But then, they could impossibly add them to exactly the same time with exactly the same quote_options

and I forgot to mention its magento 1.7

[Tim Pea]

Hi @samir_arora,

Did you ever figure this out?

We are also having what I think is the same problem, every so often a customer is able to add the same simple product to the cart twice.  We are using Magento 1.9.2.2.

I have tried testing every way I can think of adding a product (logged out / logged in / sign in on checkout)  And I can't replicate it.

Regards

Tim

[chato]

This is an old post, but for anyone who might be looking for a solution to this issue, have a look at this:

http://optimiseblog.co.uk/magento-fix-internet-explorer-adds-twice-doubl-quantity-to-cart/

This is basically caused by the IE and Firefox default button click behavior. The button click event triggers the form submit AND the onclick script, this causes the form to be submitted twice in Magento.

In: app/design/frontend/default/default/template/catalog/product/view/addtocart.phtml

Add "return false;" to the button onclick event:

<input type="image" src="<?php echo $this->getSkinUrl('add-to-basket.png') ?>"
name="image-button" onclick="productAddToCartForm.submit(); return false;" />