SVG Paths doesn't accept single Move-to command when marker-end is specified

[jnickg]

Overview

According to the SVG 1.1 specification the grammar for SVG Path data can have only one Move-to (M or m) command and a single coordinate pair. See below for example derivation, with production steps. At any point where a nonterminal is optional, it is omitted:

svg-path
moveto-drawto-command-groups
moveto-drawto-command-group
moveto
("M" | "m") moveto-argument-sequence
("M" | "m") coordinate-pair
("M" | "m") coordinate coordinate
("M" | "m") number number
("M" | "m") integer-constant integer-constant
("M" | "m") integer-constant integer-constant
("M" | "m") digit-sequence digit-sequence
("M" | "m") digit digit
("M" | "m") ("0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9") ("0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9")

However, putting sample SVG (Attached) into the SVGViewer gives the below exception. Using a Path with one more argument (Sample) renders without an exception.

System.ArgumentException was unhandled
  HResult=-2147024809
  Message=Parameter is not valid.
  Source=System.Drawing
  StackTrace:
       at System.Drawing.Drawing2D.GraphicsPath.get_PathPoints()
       at Svg.SvgPath.RenderStroke(ISvgRenderer renderer) in d:\repos\SVG\Source\Paths\SvgPath.cs:line 159
       at Svg.SvgVisualElement.Render(ISvgRenderer renderer, Boolean renderFilter) in d:\repos\SVG\Source\Basic Shapes\SvgVisualElement.cs:line 153
       at Svg.SvgVisualElement.Render(ISvgRenderer renderer) in d:\repos\SVG\Source\Basic Shapes\SvgVisualElement.cs:line 109
       at Svg.SvgElement.RenderChildren(ISvgRenderer renderer) in d:\repos\SVG\Source\SvgElement.cs:line 726
       at Svg.SvgElement.Render(ISvgRenderer renderer) in d:\repos\SVG\Source\SvgElement.cs:line 714
       at Svg.SvgFragment.Render(ISvgRenderer renderer) in d:\repos\SVG\Source\Document Structure\SvgFragment.cs:line 169
       at Svg.SvgDocument.Draw(Bitmap bitmap) in d:\repos\SVG\Source\SvgDocument.cs:line 501
       at Svg.SvgDocument.Draw() in d:\repos\SVG\Source\SvgDocument.cs:line 466
       at SVGViewer.SVGViewer.RenderSvg(SvgDocument svgDoc) in d:\repos\SVG\Samples\SVGViewer\SvgViewer.cs:line 48
       at SVGViewer.SVGViewer.open_Click(Object sender, EventArgs e) in d:\repos\SVG\Samples\SVGViewer\SvgViewer.cs:line 29
       at System.Windows.Forms.ToolStripItem.RaiseEvent(Object key, EventArgs e)
       at System.Windows.Forms.ToolStripButton.OnClick(EventArgs e)
       at System.Windows.Forms.ToolStripItem.HandleClick(EventArgs e)
       at System.Windows.Forms.ToolStripItem.HandleMouseUp(MouseEventArgs e)
       at System.Windows.Forms.ToolStripItem.FireEventInteractive(EventArgs e, ToolStripItemEventType met)
       at System.Windows.Forms.ToolStripItem.FireEvent(EventArgs e, ToolStripItemEventType met)
       at System.Windows.Forms.ToolStrip.OnMouseUp(MouseEventArgs mea)
       at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
       at System.Windows.Forms.Control.WndProc(Message& m)
       at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
       at System.Windows.Forms.ToolStrip.WndProc(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
       at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
       at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
       at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.Run(Form mainForm)
       at SVGViewer.Program.Main() in d:\repos\SVG\Samples\SVGViewer\Program.cs:line 18
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException: 

File summary:

• Sample SVG (in TXT format)
• Sample SVG with more path data (in TXT format)