Text.getMeasuredLineHeight() is 0 in IE11 and inaccurate in Chrome 44

[Inverness]

I've found that the Text.getMeasuredLineHeight() function is returning 0 in IE11 and is returning an inaccurate value (30% smaller than it should be) in Chrome 44.

I have to assume this has to do with how the rendering context is cached statically, because creating a function that uses the same methodology on a fresh context has allowed me to avoid the issue:

        static getMeasuredLineHeight(text: createjs.Text): number {
            if (!text || !text.stage || !text.stage.canvas)
                return 0;

            var canvas = <HTMLCanvasElement> text.stage.canvas;
            var ctx = canvas.getContext("2d");

            ctx.save();

            ctx.font = text.font || "10px sans-serif";
            ctx.textAlign = text.textAlign || "left";
            ctx.textBaseline = text.textBaseline || "top";
            var result = ctx.measureText("M").width * 1.2;

            ctx.restore();

            return result;
        }

[lannymcnie]

I created a quick sample to test the difference between EaselJS text and the direct context editing.

<canvas id="canvas" width="100" height="100"></canvas>

    // Test in EaselJS
    var text = new createjs.Text("M");
    var bounds = text.getBounds();

    // Test in Context directly
    var ctx = document.getElementById("canvas").getContext("2d");
    ctx.font = text.font || "10px sans-serif";
    ctx.textAlign = text.textAlign || "left";
    ctx.textBaseline = text.textBaseline || "top";
    var result = ctx.measureText("M").width * 1.2;

    console.log(bounds.height, result);

I ran the test in Chrome (latest is 46 on windows/mac), as well as IE11 (11.0.10856.0) and Edge (25.10586.0.0), all with no problems. I get slightly different heights, but they are very close (9.996 vs 9.97). Windows testing done in Windows 10.