Lower LinearRing min vertex limit to 3

[dr-jts]

Lowers the constraint on the LinearRing minimum number of vertices to 3 (from 4). This allows invalid rings to be created, so that they can be found and fixed.

This provides a resolution to #558.

See also R-sf issue 1589.

Signed-off-by: Martin Davis mtnclimb@gmail.com

[nicovanlooy]

Update corresponding exception message too in LinearRing.java:

if (getCoordinateSequence().size() >= 1 && getCoordinateSequence().size() < MINIMUM_VALID_SIZE) {  
    throw new IllegalArgumentException("Invalid number of points in LinearRing (found " 
       + getCoordinateSequence().size()
       + " - must be 0 or >= 4)");    
}

should be

if (getCoordinateSequence().size() >= 1 && getCoordinateSequence().size() < MINIMUM_VALID_SIZE) {  
    throw new IllegalArgumentException("Invalid number of points in LinearRing (found " 
       + getCoordinateSequence().size()
       + " - must be 0 or >= " + MINIMUM_VALID_SIZE + ")");    
}

[dr-jts]

Update corresponding exception message too in LinearRing.java

@nicovanlooy good point.

Fix is made in 8298604