Links is forced to open in a new window

All HTML links with target="_blank" usually means open in a new window. Some modern browser can open them in a new tab, which is one of enhancements that make Firefox famous.

But recently, the links of the page are forced to open in a new window other tan a new tab in my Firefox browser, although I have set it to open in a new tab in the Tools->option-tab.

I tried to Goolge an answer, but found nothing. Finally, I found the reason.

Try enter ‘about:config’ on your Firefox browser address bar, you will see a long list, type in ‘link’ in the Filter, you will see, below two parameters,

browser.link.open_newwindow and browser.link.open_newwindow.restriction

The default value of these two parameters are 3 and 2. But they were 1 and 1 on my browser.

browser.link.open.newwindow = 1 means open All HTML links with target="_blank" in a new tab, but it only work when browser.link.open_new.restriction = 2.