make WFS protocol and format more robust

[elemoine]

I've recently come across the case where a WFS server sends back incomplete (truncated) GetFeature responses.

In Internet Explorer this results in a js error in the XML Format's readNode method, because the node argument passed to the readNode method is null.

In FireFox this results in a js error in the GML format (in the feature["*"] reader of the GML.Base format). The error occurs later than in IE because FireFox creates a parsererror XML document when it fails to parse the XML.

The js error can be reproduced, both in FF and IE, with the test_badxml test in test.patch .

Patch to follow.

[elemoine]

IE.patch fixes it in Internet Explorer. FF.patch fixes it in FireFox.

Please review. I think test.patch need not be committed - t.plan(0) being a bit weird. I attached it just to make it easy to reproduce the error.

[ahocevar]

Both FF.patch and IE.patch look safe to me. Not sure if they improve things in real life conditions, but since they don't do any harm, I'd say please commit.

I agree that test.patch is not needed.

[elemoine]

Replying to ahocevar:

Both FF.patch and IE.patch look safe to me. Not sure if they improve things in real life conditions,

they do. In a context where you don't control the WFS servers and where the WFS servers return bad XML, with this patch you don't end up with js errors making your app in an unpredictable state.

but since they don't do any harm, I'd say please commit. I agree that test.patch is not needed.

Thanks a lot for the review.

[elemoine]

(In [9636]) make WFS protocol and format more robust, r=ahocevar (closes #2237)