fix(editor): guard the places where the editor could crash outright

Found with an address and undefined behaviour sanitizer build, random
monkey sessions on the test sceneries and broken inputs:

- A deleted model left its pointer in the pick list of the renderer, the
  bound node of the panels, the bindings of the infrastructure and the
  selection: the next pick or panel frame read freed memory. The renderer
  forgets it, and one erase_model does the cleaning for all the places
  which deleted a model by hand.
- The plan band of a route read the vertex before the first one in the
  frame a drag was let go.
- A scenery which can't be opened goes back to the launcher with the
  reason in the log, a track of an unknown type or a tributary loads as
  a normal track or a river with a message, and a spline with no finite
  length or step gets a sane number of segments.
- Typed numbers which aren't (NaN, inf, ends 0 m or 1000 km apart, a
  vector of 1e30, a diverging track part of 5 km, a curve threshold of 0,
  a zero history size, radius norms below zero) are refused or clamped,
  where they made the geometry run away or divide by zero.
- Folders which can't be read and file names which aren't valid in the
  locale no longer throw out of the scans of sceneries, textures, sweeps,
  roads and signal plates; the scans skip them.
- The launcher: Ctrl+Del with no trainset selected, a dropped vehicle
  whose skin is gone and a text with a percent sign.
- A terrain mesh made for another resolution of its chunk isn't put into
  the chunk, and a slot is reused only for a mesh of the same size.
- Vehicles on a track changed by the editor are moved over a copy of the
  list they leave.
- The table of the keyboard shortcuts gives its stretched column a
  weight, else ImGui divides 0 by 0 in the first frame of the window.

application/editormodetrack.cpp

@@ -1345,6 +1345,7 @@ void editor_mode::render_path_ui()
 		}
 	};
 
+	auto const finite = [](glm::dvec3 const &Point) { return std::isfinite(Point.x) && std::isfinite(Point.y) && std::isfinite(Point.z); };
 	if (ImGui::CollapsingHeader(track->eType == tt_Switch ? STR_C("Geometry of the paths") : STR_C("Geometry")))
 	{
 		for (int i = 0; i < static_cast<int>(track->m_paths.size()); ++i)
@@ -1381,7 +1382,7 @@ void editor_mode::render_path_ui()
 				if (editor_track::is_end(kind))
 				{
 					auto position = path.points[kind == editor_track::point_kind::start ? segment_data::point::start : segment_data::point::end];
-					if (ImGui::DragScalarN("x, y, z##point", ImGuiDataType_Double, glm::value_ptr(position), 3, 0.01f, nullptr, nullptr, "%.3f"))
+					if (ImGui::DragScalarN("x, y, z##point", ImGuiDataType_Double, glm::value_ptr(position), 3, 0.01f, nullptr, nullptr, "%.3f") && finite(position))
 						editor_track::move_point(*track, m_track_point, position);
 					item_tooltip("Drag to move, Ctrl+click to type the value");
 					finish_edit(rebuild::geometry);
@@ -1389,7 +1390,9 @@ void editor_mode::render_path_ui()
 				else
 				{
 					auto &vector{path.points[kind == editor_track::point_kind::control1 ? segment_data::point::control1 : segment_data::point::control2]};
-					ImGui::DragScalarN(STR_C("vector##point"), ImGuiDataType_Double, glm::value_ptr(vector), 3, 0.01f, nullptr, nullptr, "%.3f");
+					auto typed{vector};
+					if (ImGui::DragScalarN(STR_C("vector##point"), ImGuiDataType_Double, glm::value_ptr(typed), 3, 0.01f, nullptr, nullptr, "%.3f") && finite(typed) && glm::length(typed) < 1e5)
+						vector = typed;
 					item_tooltip("Control vector, relative to its end; zero for a straight");
 					finish_edit(rebuild::geometry);
 				}
@@ -1399,11 +1402,13 @@ void editor_mode::render_path_ui()
 				if (begin_fields("##cantradius", 0.3f))
 				{
 					field_row("Roll (deg)");
-					ImGui::DragFloat2("##roll", path.rolls.data(), 0.01f, -15.0f, 15.0f, "%.2f");
+					if (auto rolls{path.rolls}; ImGui::DragFloat2("##roll", rolls.data(), 0.01f, -15.0f, 15.0f, "%.2f") && std::isfinite(rolls[0]) && std::isfinite(rolls[1]))
+						path.rolls = rolls;
 					item_tooltip("Cant at the start and at the end as the roll angle of the track");
 					finish_edit(rebuild::geometry);
 					field_row("Radius");
-					ImGui::InputFloat("##radius", &path.radius, 0.0f, 0.0f, "%.1f");
+					if (auto radius{path.radius}; ImGui::InputFloat("##radius", &radius, 0.0f, 0.0f, "%.1f") && std::isfinite(radius))
+						path.radius = radius;
 					item_tooltip("Radius stored with the path in the scenery; the shape itself comes from the control vectors");
 					finish_edit(rebuild::geometry);
 					ImGui::EndTable();