From 60595e13419bf86bb2f71731852123fa2ca1991c Mon Sep 17 00:00:00 2001
From: BobLd <boris.ledeist@edhec.com>
Date: Sun, 5 Apr 2020 11:07:02 +0100
Subject: [PATCH] Check if current path is null for path construction operators

---
 .../PathConstruction/AppendDualControlPointBezierCurve.cs       | 2 ++
 .../PathConstruction/AppendEndControlPointBezierCurve.cs        | 2 ++
 .../PathConstruction/AppendStartControlPointBezierCurve.cs      | 2 ++
 .../Operations/PathConstruction/AppendStraightLineSegment.cs    | 2 ++
 4 files changed, 8 insertions(+)

diff --git a/src/UglyToad.PdfPig/Graphics/Operations/PathConstruction/AppendDualControlPointBezierCurve.cs b/src/UglyToad.PdfPig/Graphics/Operations/PathConstruction/AppendDualControlPointBezierCurve.cs
index 0a4a23f0..0c2a6b72 100644
--- a/src/UglyToad.PdfPig/Graphics/Operations/PathConstruction/AppendDualControlPointBezierCurve.cs
+++ b/src/UglyToad.PdfPig/Graphics/Operations/PathConstruction/AppendDualControlPointBezierCurve.cs
@@ -71,6 +71,8 @@
         /// <inheritdoc />
         public void Run(IOperationContext operationContext)
         {
+            if (operationContext.CurrentSubpath == null) return;
+
             var controlPoint1 = operationContext.CurrentTransformationMatrix.Transform(new PdfPoint(X1, Y1));
             var controlPoint2 = operationContext.CurrentTransformationMatrix.Transform(new PdfPoint(X2, Y2));
             var end = operationContext.CurrentTransformationMatrix.Transform(new PdfPoint(X3, Y3));
diff --git a/src/UglyToad.PdfPig/Graphics/Operations/PathConstruction/AppendEndControlPointBezierCurve.cs b/src/UglyToad.PdfPig/Graphics/Operations/PathConstruction/AppendEndControlPointBezierCurve.cs
index a360711a..e1a2622a 100644
--- a/src/UglyToad.PdfPig/Graphics/Operations/PathConstruction/AppendEndControlPointBezierCurve.cs
+++ b/src/UglyToad.PdfPig/Graphics/Operations/PathConstruction/AppendEndControlPointBezierCurve.cs
@@ -56,6 +56,8 @@
         /// <inheritdoc />
         public void Run(IOperationContext operationContext)
         {
+            if (operationContext.CurrentSubpath == null) return;
+
             var controlPoint1 = operationContext.CurrentTransformationMatrix.Transform(new PdfPoint(X1, Y1));
             var end = operationContext.CurrentTransformationMatrix.Transform(new PdfPoint(X3, Y3));
             operationContext.CurrentSubpath.BezierCurveTo(controlPoint1.X, controlPoint1.Y, end.X, end.Y, end.X, end.Y);
diff --git a/src/UglyToad.PdfPig/Graphics/Operations/PathConstruction/AppendStartControlPointBezierCurve.cs b/src/UglyToad.PdfPig/Graphics/Operations/PathConstruction/AppendStartControlPointBezierCurve.cs
index 61d1dd9b..22c03bb4 100644
--- a/src/UglyToad.PdfPig/Graphics/Operations/PathConstruction/AppendStartControlPointBezierCurve.cs
+++ b/src/UglyToad.PdfPig/Graphics/Operations/PathConstruction/AppendStartControlPointBezierCurve.cs
@@ -56,6 +56,8 @@
         /// <inheritdoc />
         public void Run(IOperationContext operationContext)
         {
+            if (operationContext.CurrentSubpath == null) return;
+
             var controlPoint2 = operationContext.CurrentTransformationMatrix.Transform(new PdfPoint(X2, Y2));
             var end = operationContext.CurrentTransformationMatrix.Transform(new PdfPoint(X3, Y3));
             operationContext.CurrentSubpath.BezierCurveTo(operationContext.CurrentPosition.X,
diff --git a/src/UglyToad.PdfPig/Graphics/Operations/PathConstruction/AppendStraightLineSegment.cs b/src/UglyToad.PdfPig/Graphics/Operations/PathConstruction/AppendStraightLineSegment.cs
index 93a9c201..efb33483 100644
--- a/src/UglyToad.PdfPig/Graphics/Operations/PathConstruction/AppendStraightLineSegment.cs
+++ b/src/UglyToad.PdfPig/Graphics/Operations/PathConstruction/AppendStraightLineSegment.cs
@@ -41,6 +41,8 @@
         /// <inheritdoc />
         public void Run(IOperationContext operationContext)
         {
+            if (operationContext.CurrentSubpath == null) return;
+
             var endPoint = operationContext.CurrentTransformationMatrix.Transform(new PdfPoint(X, Y));
             operationContext.CurrentSubpath.LineTo(endPoint.X, endPoint.Y);
             operationContext.CurrentPosition = endPoint;