Prevent stack overflow when selecting mesh elements (Stop recursive ToString() on mesh handles)

[Aleph0x]

Selecting mesh elements (edges, faces, vertices) with trace logging enabled could flood the console and eventually crash with:

System.InsufficientExecutionStackException: Insufficient stack to continue executing the program safely.

This fixes the cause by changing ToString() on mesh selection wrapper types so they no longer invoke handle ToString() implementations that recursively walk/traverse the half-edge mesh structure.

The mesh selection wrapper types MeshEdge, MeshFace, and MeshVertex were formatting their underlying handle objects directly inside interpolated strings.

MeshEdge.ToString() included {Handle} where Handle is a HalfEdgeHandle

MeshFace.ToString() included {Handle} where Handle is a FaceHandle

MeshVertex.ToString() included {Handle} where Handle is a VertexHandle

Interpolating {Handle} calls Handle.ToString().

From the stacktraces, those handle ToString() implementations go through PrintMembers(StringBuilder ...), typical of record style or debugger display helpers. Those routines then stringify connected handles. Half edges reference vertices, vertices reference half edges, and so on. So we end up with an unbounded call stack until the runtime throws InsufficientExecutionStackException or at least until Trace Logging is disabled in the scene editor.

Error calling event 'tool.frame' on 'Editor.SceneViewWidget'
System.InsufficientExecutionStackException: Insufficient stack to continue executing the program safely. This can happen from having too many functions on the call stack or function on the stack using too much stack space.
     at HalfEdgeMesh.HalfEdgeHandle.PrintMembers(StringBuilder builder)
   at HalfEdgeMesh.HalfEdgeHandle.ToString()
   at HalfEdgeMesh.VertexHandle.PrintMembers(StringBuilder builder)
   at HalfEdgeMesh.VertexHandle.ToString()
   ...
   at System.Runtime.CompilerServices.DefaultInterpolatedStringHandler.AppendFormatted[T](T value)
   at Editor.MeshEditor.MeshEdge.ToString() in C:\program files (x86)\steam\steamapps\common\sbox\addons\tools\code\Scene\Mesh\MeshEdge.cs:line 36
   at System.String.FormatHelper(IFormatProvider provider, String format, ReadOnlySpan`1 args)
   at Editor.TreeView.ScrollTo(Object target) in C:\program files (x86)\steam\steamapps\common\sbox\addons\tools\code\Widgets\TreeView\TreeView.cs:line 706
   at Editor.SceneTreeWidget.OnInspect(OnInspectArgs args) in C:\program files (x86)\steam\steamapps\common\sbox\addons\tools\code\Scene\SceneTree\SceneTree.cs:line 262
   at Editor.EditorUtility.set_InspectorObject(Object value)
   at Editor.SceneViewWidget.Frame() in C:\program files (x86)\steam\steamapps\common\sbox\addons\tools\code\Scene\SceneView\SceneViewWidget.cs:line 96
   at InvokeStub_SceneViewWidget.Frame(Object, Object, IntPtr*)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)

[aylaylay]

I'd rather the handles just had a tostring for the index incase they get logged by someone

[Aleph0x]

I'd rather the handles just had a tostring for the index incase they get logged by someone

I’ll shift the fix

[aylaylay]

put these on single line

[Aleph0x]

41f7032#diff-d17893cdfeca36175db7ca45a7265fc849ca183dbe13de771ba56c475ccd60e5