MapServer WFS should not output LineString with a single coordinate

[dmorissette]

Paul Ramsey wrote:
> 
> So, I downloaded CadCorp MapBrowser, and it worked with mapserver 4.4 
> and 4.6. Only one problem, and that was when it was given a LineString 
> with only one coordinate (not legal GML). Which is a data or a server 
> problem, depending on where one wants to point fingers.
>

[dmorissette]

MapServer should probably produce an error (or exception) in mapgml.c instead of
returning a LineString with a single vertex. 

[sdlime]

Similarly it should not output a polygon with 2 verts. There's not a good way 
to report errors like this midway through outputing a document. Would it be 
enough to output a warning comment and then carry on?

Since I'd point the finger at the data guy do you want to hold up 4.6? I'd say 
no.

[refractions]

Don't hold 4.6, this has an obvious workaround (fix your data). Some kind of
warning emitted would be good (this is where mapserver log levels can be great))
but it is a hard balancing act: simply dying is mean, but silently "fixing" or
omitting the feature is also mean.

[dmorissette]

Steve, would you want to take this bug since you were the last one to play in
the GML code?

[sdlime]

Will do... I think a warning (and no feature) is about as good as we can do.
Will add to 4.7 first and then back port.

Steve

[sdlime]

I checked and there is no check for degenerate features of any type (e.g. 2 point polygons, 1 point lines etc...). It doesn't seem to be a huge problem so I'm marking as wontfix at this point. Can always reopen if necessary.

Steve