No tabindex
Negative tabindex
Results of Opera:
No tabindex: [object HTMLBodyElement]
Negative tabindex: [object HTMLDivElement]
Results of Firefox:
No tabindex: [object HTMLBodyElement]
Negative tabindex: [object HTMLDivElement]
Results of Internet Explorer:
No tabindex: [object HTMLBodyElement]
Negative tabindex: [object HTMLDivElement]
Conclusion: no tabindex and negative tabindex are treated differently.
Therefore the default tabIndex IDL value for non-focusable elements is not -1.
And it shouldn't be, or else by default all elements would be focusable (as tabindex value of
-1 means it must be focusable).