This tests that text drawn with text-shadows of radius 0 and (0, 0) offset are not drawn.

In the following tests, the actual text is green while the shadows are blue.

Text with a single shadow.

Text with one empty (undrawn) shadow.

Text with two shadows

Text with two shadows: first drawn and second empty (undrawn).

Text with two shadows: first empty (undrawn) and second drawn.

Text with two empty (undrawn) shadows.

Transparent text with a single shadow.

Transparent text with one empty shadow.

Transparent text with two shadows

Transparent text with two shadows: first drawn and second empty.

Transparent text with two empty shadows.