Linestring draws filled in IE

[euzuro]

As reported by Benoit M to the user's list:

I'm experiencing a strange behavior with OpenLayers' Vector layer
based upon OpenLayers Feature. Dunno if I'm any understandable but
anyway, here is what I do:

 var points = [];
 points.push(new OpenLayers.Geometry.Point(1, 2));
 // ...
 var target = new OpenLayers.Layer.Vector("My layer");
 map.addLayer(target);
 target.addFeatures([new OpenLayers.Feature.Vector(
          new OpenLayers.Geometry.LineString(points))]);

And I end up with a nice line in Firefox and IE7 but with a
white-filled polygon in IE6 [1]. Strangely, the white-fill
disappears once I zoom in [2] and does *not*
reappear when I zoom out.

[1] http://88.191.48.4/feature_1.jpeg
[2] http://88.191.48.4/feature_2.jpeg

[euzuro]

from cr5:

when I looked into it, I found that
the same VML ended up behaving differently when the page first loaded
than from later, and I never figured out why.

[euzuro]

more from benoit:

For people looking for a workaround, I use the following code:

 window.setTimeout(function() {
     myLayer.setVisibility(false);
     myLayer.setVisibility(true);
   }, 1000);

[crschmidt]

It appears that VML implements lines as filled polys, with the fill being equivilant to the background color of the poly at the time it was drawn. (this is 'fake' transparency.) Because the background color is white when the feature is drawn, it stays white even after the image loads in.

This happens in other VML demos on the web too, so I'm willing to call this a "wontfix", unless others have better ideas.

[bphilippot]

This patch corrects the bug replacing in VML.js :
- fillcolor:none with filled="false" if options.isFilled is false
- strokecolor:none with stroked="false" if options.isStroked is false

[elemoine]

Replying to pgiraud:

I'm in favour of this patch as long as it doesn't break things on IE 7.

Also, I was going to suggest to write some test for this bug, when I realized there is currently no test for the SVG and VML renderers. It'd probably be worse implementing some. FWIW, Layer/test_Vector.js already has some SVG/VML tests that one may want to look at beforehands.

[tschaub]

I'm incorporating this in to the patch for #1042, as the problem is highlighted when that issue is addressed.