According to my research:
As per OP Request i have tested it. And it works. If the pop-up blocker is enabled i will catch it and therefore i will get a reliable way to know that it is enabled. In this case i am just sending an alert, but you can do whatever you wish.
Here is the code:
Testing Pop-up Blocker
Testing Pop-up Blocker
And here is what i got, because the pop-up blocker was enabled.