description("Test the handling of negative sourceRect offset in getImageData().");

ctx = document.createElement('canvas').getContext('2d');

ctx.fillStyle = 'red';
ctx.fillRect(0, 0, 100, 100);
ctx.fillStyle = 'green';
ctx.fillRect(0, 0, 6, 6);

var imageData = ctx.getImageData(-10, 0, 100, 1);
var imgdata = imageData.data;

// Fully transparent black
shouldBe("imgdata[0]", "0");
shouldBe("imgdata[1]", "0");
shouldBe("imgdata[2]", "0");
shouldBe("imgdata[3]", "0");

// Green
shouldBe("imgdata[60]", "0");
shouldBe("imgdata[61]", "128");
shouldBe("imgdata[62]", "0");
shouldBe("imgdata[63]", "255");

// Red
shouldBe("imgdata[64]", "255");
shouldBe("imgdata[65]", "0");
shouldBe("imgdata[66]", "0");
shouldBe("imgdata[67]", "255");