I haven’t made any changes to that file. Where did you find that problem?
Have you updated woocommerce on your demo theme?
Also, I have found a problem with the widths of the buttons and borders. It wasn’t rendering properly in some browsers.
<div class=”quantity buttons_added”>
<input class=”minus” type=”button” value=”-“>
<input class=”input-text qty text” type=”number” title=”Qty” value=”1″ name=”quantity” min=”1″ step=”1″>
<input class=”plus” type=”button” value=”+”>
</div>
The above buttons and border widths add up to 110px. The theme css is marked as 109px. Here is the fix:
.woocommerce .quantity, .woocommerce-page .quantity {
max-width: 110px;
}
.