<div dir="ltr">We're in the process of porting RelateNG [1] to GEOS [2].  It offers benefits of performance, robustness, and increased functionality (e.g. handling GeometryCollections).<div><br></div><div>RelateNG does have one slight change in semantics.  It treats a Zero-Length Line to be topologically equal to a Point:</div><div><br></div><div><font face="monospace">equalsTopo( LINESTRING(1 1, 1 1),  POINT(1 1) ) = TRUE</font></div><div><br></div><div>(the XML test for this is here: <a href="https://github.com/libgeos/geos/blob/main/tests/xmltester/tests/validate/TestRelatePL.xml#L43">https://github.com/libgeos/geos/blob/main/tests/xmltester/tests/validate/TestRelatePL.xml#L43</a>)</div><div><br></div><div>Note that RelateNG does fix some other issues with Zero-Length Lines, as discussed in these issues:</div><div><a href="https://github.com/locationtech/jts/issues/345">https://github.com/locationtech/jts/issues/345</a></div><div><a href="https://github.com/locationtech/jts/issues/1050">https://github.com/locationtech/jts/issues/1050</a></div><div><br></div><div>So the question is:  does anyone see any problems with allowing Zero-Length Lines to test as equal to Points?</div><div><br></div><div>(Note: my opinion is that this is a beneficial change).</div><div><br></div><div>[1] <a href="https://lin-ear-th-inking.blogspot.com/2024/05/jts-topological-relationships-next.html">https://lin-ear-th-inking.blogspot.com/2024/05/jts-topological-relationships-next.html</a></div><div>[2] <a href="https://github.com/libgeos/geos/tree/main-relate-ng">https://github.com/libgeos/geos/tree/main-relate-ng</a></div></div>