Merge branch 'edgelord' into 'master'

Fix UB when pathgrid geometry is generated and all pathgrid edges are invalid

See merge request OpenMW/openmw!4541

Author: psi29a

components/sceneutil/pathgridutil.cpp

@@ -126,9 +126,9 @@ namespace SceneUtil
 
             gridGeometry->setVertexArray(vertices);
             gridGeometry->setColorArray(colors, osg::Array::BIND_PER_VERTEX);
-            if (pointIndexCount)
+            if (!pointIndices->empty())
                 gridGeometry->addPrimitiveSet(pointIndices);
-            if (edgeIndexCount)
+            if (!lineIndices->empty())
                 gridGeometry->addPrimitiveSet(lineIndices);
             gridGeometry->getOrCreateStateSet()->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
         }