From e091b30707c83b6cbd483e8cb673394c9e1c3452 Mon Sep 17 00:00:00 2001
From: Nikolaj Olsson <nikse.dk@gmail.com>
Date: Wed, 4 Mar 2020 16:05:16 +0100
Subject: [PATCH] Fix "Batch convert" issue with new auto-br optimzation

---
 libse/TextSplitResult.cs | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/libse/TextSplitResult.cs b/libse/TextSplitResult.cs
index 2788332e0..219b6e6c1 100644
--- a/libse/TextSplitResult.cs
+++ b/libse/TextSplitResult.cs
@@ -17,6 +17,7 @@ namespace Nikse.SubtitleEdit.Core
 
         private static readonly Graphics Graphics = Graphics.FromHwnd(IntPtr.Zero);
         private static readonly Font DefaultFont = SystemFonts.DefaultFont;
+        private static readonly object GdiLock = new object();
 
         public TextSplitResult(List<string> lines)
         {
@@ -24,15 +25,24 @@ namespace Nikse.SubtitleEdit.Core
             LengthPixels = new List<float>();
             if (Configuration.Settings.Tools.AutoBreakUsePixelWidth)
             {
-                var lineOneWidth = Graphics.MeasureString(Lines[0], DefaultFont).Width;
-                LengthPixels.Add(lineOneWidth);
+                lock (GdiLock)
+                {
+                    var lineOneWidth = Graphics.MeasureString(Lines[0], DefaultFont).Width;
+                    LengthPixels.Add(lineOneWidth);
+                }
 
-                var lineTwoWidth = Graphics.MeasureString(Lines[1], DefaultFont).Width;
-                LengthPixels.Add(lineTwoWidth);
+                lock (GdiLock)
+                {
+                    var lineTwoWidth = Graphics.MeasureString(Lines[1], DefaultFont).Width;
+                    LengthPixels.Add(lineTwoWidth);
+                }
 
                 if (Math.Abs(SpaceLengthPixels) < 0.01)
                 {
-                    SpaceLengthPixels = Graphics.MeasureString(" ", DefaultFont).Width;
+                    lock (GdiLock)
+                    {
+                        SpaceLengthPixels = Graphics.MeasureString(" ", DefaultFont).Width;
+                    }
                 }
             }