There are a dozen or more threads about this in the Ebay seller forums.
To say the least, this is inconvenient.
To me, this is an indication LastPass is not as attentive to security issues as it should be. Why would it want any amount of its coding to be exposed?
There are no fields to autofill, no username or password field, on an Ebay listing form. The code is injected into an edit window for a listing. LastPass is an uninvited visitor.
As I've said before, the code from LastPass is not injected into edit windows on any other form, including those that appears on pages where there is a username or password field. This behavior is peculiar to LastPass in relation to Ebay only.
What part of "unfortunate side effect" do you not understand? I didn't say it's correct behavior. LastPass injects this code into *every* ebay webpage in order to *find* login fields if any exists. It doesn't know a priori if login fields exist on the page. It just so happens that in the listing editing page, the code somehow ended up in the edit window.
I was only replying to your question of why LastPass does this, and why it's not a security issue. I was NOT commenting on the more general problem of the code ending up in listings.
Whether or not there's login fields on the page has no relevance. As I said before, part of the purpose of the code is to find out whether there's a login field. Injected code is site-specific, not page-specific.