Clamp NavigationMesh sample_distance above zero

While default ReCast library has support for 0.0 'sample_distance' the Godot implementation does not an crashes.
Previously Godot would set all sample_distance values below 0.9 to 0 which causes the crashes.

This limits the sample_distance range selection to 0.1 - 16.0 and also clamps sample_distance that are below 0.1 before ReCast receives them.

(cherry picked from commit e33fa9d8331f38c8c404b9d6ea286eacb503d3bb)

modules/navigation/navigation_mesh_generator.cpp

@@ -447,7 +447,7 @@ void NavigationMeshGenerator::_build_recast_navigation_mesh(
 	cfg.minRegionArea = (int)(p_nav_mesh->get_region_min_size() * p_nav_mesh->get_region_min_size());
 	cfg.mergeRegionArea = (int)(p_nav_mesh->get_region_merge_size() * p_nav_mesh->get_region_merge_size());
 	cfg.maxVertsPerPoly = (int)p_nav_mesh->get_verts_per_poly();
-	cfg.detailSampleDist = p_nav_mesh->get_detail_sample_distance() < 0.9f ? 0 : p_nav_mesh->get_cell_size() * p_nav_mesh->get_detail_sample_distance();
+	cfg.detailSampleDist = MAX(p_nav_mesh->get_cell_size() * p_nav_mesh->get_detail_sample_distance(), 0.1f);
 	cfg.detailSampleMaxError = p_nav_mesh->get_cell_height() * p_nav_mesh->get_detail_sample_max_error();
 
 	cfg.bmin[0] = bmin[0];

scene/resources/navigation_mesh.cpp

@@ -223,7 +223,7 @@ float NavigationMesh::get_verts_per_poly() const {
 }
 
 void NavigationMesh::set_detail_sample_distance(float p_value) {
-	ERR_FAIL_COND(p_value < 0);
+	ERR_FAIL_COND(p_value < 0.1);
 	detail_sample_distance = p_value;
 }
 
@@ -494,7 +494,7 @@ void NavigationMesh::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::REAL, "edge/max_length", PROPERTY_HINT_RANGE, "0.0,50.0,0.01,or_greater"), "set_edge_max_length", "get_edge_max_length");
 	ADD_PROPERTY(PropertyInfo(Variant::REAL, "edge/max_error", PROPERTY_HINT_RANGE, "0.1,3.0,0.01,or_greater"), "set_edge_max_error", "get_edge_max_error");
 	ADD_PROPERTY(PropertyInfo(Variant::REAL, "polygon/verts_per_poly", PROPERTY_HINT_RANGE, "3.0,12.0,1.0,or_greater"), "set_verts_per_poly", "get_verts_per_poly");
-	ADD_PROPERTY(PropertyInfo(Variant::REAL, "detail/sample_distance", PROPERTY_HINT_RANGE, "0.0,16.0,0.01,or_greater"), "set_detail_sample_distance", "get_detail_sample_distance");
+	ADD_PROPERTY(PropertyInfo(Variant::REAL, "detail/sample_distance", PROPERTY_HINT_RANGE, "0.1,16.0,0.01,or_greater"), "set_detail_sample_distance", "get_detail_sample_distance");
 	ADD_PROPERTY(PropertyInfo(Variant::REAL, "detail/sample_max_error", PROPERTY_HINT_RANGE, "0.0,16.0,0.01,or_greater"), "set_detail_sample_max_error", "get_detail_sample_max_error");
 
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "filter/low_hanging_obstacles"), "set_filter_low_hanging_obstacles", "get_filter_low_hanging_obstacles");