Problems with redraw on a logo programming website

[WildKeccak]

Where:
​http://calormen.com/jslogo/

Description:

1) Clearscreen command doesn't work
2) There is a black box on the screen that appears at the start or after a program is run.
3) The turtles don't go away.
4) Going fullscreen or resizing the window clears the screen.

To replicate:
1) Open the site
2) Click on the underlined word star on the right
3) Click the run button underneath the "canvas"

1) Click the clear button to empty the "code area"
2) Enter clearscreen where it says "Type in your code here..."
3) Click the run button

1) Press alt-Enter
2) Press alt-Enter again.

You should be able to see all of the problems described.

[WildKeccak]

Drawing a star

[WildKeccak]

Drawing a wreath with the turtles that are left behind.

[WildKeccak]

Drawing after running clearscreen window hideturtle. The original is there still, and a partial mitigation.

[WildKeccak]

Another screenshot, this one of the fern

[WildKeccak]

This is a horrible creation I call Ninja Turtle. It is a meditation on why I don't see a small wreath, but I do see that one turtle.

[cocobean]

Tested on hrev54202. Specific to WebPositive 1.1-alpha (tested with WebKit 608.1.6). Works properly with Otter Browser 1.0.01.

[WildKeccak]

The Brave search engine says in the summary that this uses SVG. That is probably useful to know.

[nephele]

This wasn't on my radar at all because of the wrong component :)