BitmapData.copy problem on iOS

[Marsu]

I am starting to go insane... 

All day I have tried to get this to work, but it doesn't. I am working on a drawing game which already works quite well. The drawing surface is a sprite with a BitmapData as texture and gets drawn on during move callbacks. 

It also has an undo-function which works fine on desktop and inside an android webview. But on iOS the "recording" of undo-states does not work at all. 

Essentially on starting the next stroke (input down) or on clearing the image, the whole BitmapData gets copied into a new BD which is pushed into an array (which gets shifted first if the number of undo-states exceeds X)

on undo the last undo-state gets copied back to the main BD.

if (this.undoSteps.length >= this.maxUndoSteps) {
			this.undoSteps.shift();
		}

		var undoStepNew = this.game.add.bitmapData(this.drawImg.width, this.drawImg.height, '', true);
		undoStepNew.blendSourceOver();
undoStepNew.copyRect(this.drawImg, new Phaser.Rectangle(0, 0, this.drawImg.width, this.drawImg.height), 0, 0, 1, "source-over");
this.undoSteps.push(undoStepNew);

I tried different blend-modes, tried copy, draw, pulling directly from the BD instead of the Sprite it is assigned to, pulling from the texture field, everything.

Most of what I tried worked fine on desktop (chrome) and android (4.4.x), but never on this damn iPhone 5. 

Any Ideas what the problem could be?

[Marsu]

Through much trial and error I found a solution.

If I copied not from the other Image, Sprite or BitmapData but directly from Object.texture.baseTexture.source (a DOM canvas), it works on the iPhone. 

Should I consider this a bug and report it?