See the original report in https://github.com/facebook/react/issues/10772#issuecomment-333242375.

The problem is that SVG is case sensitive, and so naïvely setting `tabIndex` and relying on insensitivity won't work with it.

The good news is it seems like `tabindex` is the only valid [SVG attribute](https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute) with this problem. We just missed it because it applies both to HTML and SVG.

I think the fix is to add it back to the whitelist. 
}
            },
          };
        },
      };
      let e = await render(threeDivIterable);
      let parent = e.parentNode;
      expect(parent.childNodes.length).toBe(3);
      expect(parent.childNodes[0].tagName).toBe('DIV');
      expect(parent.childNodes[1].tagName).toBe('DIV');
      expect(parent.childNodes[2].tagName).toBe('DIV');
    });
    itRenders('emptyish values', async render => {
      let e = await render(0);
      expect(e.nodeType).toBe(TEXT_NODE_TYPE);
      expect(e.nodeValue).toMatch('0');
      
      
      expect((await render(<div>{''}</div>)).textContent).toBe('');
      expect(await render([])).toBe(null);
      expect(await render(false)).toBe(null);
      expect(await render(true)).toBe(null);
      expect(await render(undefined)).toBe(null);
      expect(await render([[[false]], undefined])).toBe(null);
    });
  });
  describe('property to attribute mapping', function() {
    describe('string properties', function() {
      itRenders('simple numbers', async render => {
        const e = await render(<div width={30} />);