Prompt when cancelling OCR window - thx Zwulf :)

LanguageMaster.xml

@@ -2032,6 +2032,8 @@ Keep changes?</KeepChangesMessage>
     <InspectCompareMatchesForCurrentImage>Inspect compare matches for current image...</InspectCompareMatchesForCurrentImage>
     <EditLastAdditions>Edit last image compare additions...</EditLastAdditions>
     <SetUnitalicFactor>Set un-italic factor...</SetUnitalicFactor>
+    <DiscardTitle>Discard changes made in OCR?</DiscardTitle>
+    <DiscardText>Do you want to discard changes made in current OCR session?</DiscardText>
   </VobSubOcr>
   <VobSubOcrCharacter>
     <Title>VobSub - Manual image to text</Title>

src/Forms/VobSubOcr.cs

@@ -291,6 +291,9 @@ namespace Nikse.SubtitleEdit.Forms
         private int _tesseractAsyncIndex;
         private BackgroundWorker _tesseractThread;
 
+        private DateTime _windowStartTime = DateTime.Now;
+        private int _linesOcred = 0;
+
         public static void SetDoubleBuffered(Control c)
         {
             //Taxes: Remote Desktop Connection and painting http://blogs.msdn.com/oldnewthing/archive/2006/01/03/508694.aspx
@@ -1275,6 +1278,19 @@ namespace Nikse.SubtitleEdit.Forms
                     foreach (string fn in fileNames)
                     {
                         string fullFileName = Path.Combine(Path.GetDirectoryName(_bdnFileName), fn);
+                        if (!File.Exists(fullFileName))
+                        {
+                            // fix AVISubDetector lines
+                            int idxOfIEquals = fn.IndexOf("i=", StringComparison.OrdinalIgnoreCase);
+                            if (idxOfIEquals >= 0)
+                            {
+                                int idxOfSpace = fn.IndexOf(' ', idxOfIEquals);
+                                if (idxOfSpace > 0)
+                                {
+                                    fullFileName = Path.Combine(Path.GetDirectoryName(_bdnFileName), fn.Remove(0, idxOfSpace).Trim());
+                                }
+                            }
+                        }
                         if (File.Exists(fullFileName))
                         {
                             try
@@ -4950,6 +4966,7 @@ namespace Nikse.SubtitleEdit.Forms
 
         private void ButtonOkClick(object sender, EventArgs e)
         {
+            _linesOcred = 0; // don't ask about discard changes
             if (_dvbSubtitles != null && checkBoxTransportStreamGetColorAndSplit.Checked)
                 MergeDvbForEachSubImage();
 
@@ -5538,6 +5555,8 @@ namespace Nikse.SubtitleEdit.Forms
                     text = "<font color=\"" + ColorTranslator.ToHtml(_dvbSubColor) + "\">" + text + "</font>";
             }
 
+            _linesOcred++;
+
             if (_abort)
             {
                 textBoxCurrentText.Text = text;
@@ -7788,8 +7807,40 @@ namespace Nikse.SubtitleEdit.Forms
             subtitleListView1.SelectIndexAndEnsureVisible(0);
         }
 
+        private bool HasChangesBeenMade()
+        {
+            var secondsSinceOcrWindowOpened = DateTime.Now.Subtract(_windowStartTime).TotalSeconds;
+            if (_subtitle != null && _subtitle.Paragraphs.Count > 10 && secondsSinceOcrWindowOpened > 10)
+            {
+                int numberOfLinesWithText = 0;
+                foreach (var p in _subtitle.Paragraphs)
+                {
+                    if (p != null && !string.IsNullOrWhiteSpace(p.Text))
+                    {
+                        numberOfLinesWithText++;
+                    }
+                }
+
+                // ocr'ed more than 10 lines - or perhaps manually translated more than 10 lines in at least 30 seconds
+                if (_linesOcred > 10 || (numberOfLinesWithText > 10 && secondsSinceOcrWindowOpened > 30))
+                {
+                    return true;
+                }
+            }
+            return false;
+        }
+
         private void VobSubOcr_FormClosing(object sender, FormClosingEventArgs e)
         {
+            if (HasChangesBeenMade())
+            {
+                if (MessageBox.Show(Configuration.Settings.Language.VobSubOcr.DiscardText, Configuration.Settings.Language.VobSubOcr.DiscardTitle, MessageBoxButtons.YesNo) == DialogResult.No)
+                {
+                    e.Cancel = true;
+                    return;
+                }
+            }
+
             _icThreadsStop = true;
             _abort = true;
             _nocrThreadsStop = true;

src/Logic/Language.cs

@@ -2345,6 +2345,8 @@ Keep changes?",
                 InspectCompareMatchesForCurrentImage = "Inspect compare matches for current image...",
                 EditLastAdditions = "Edit last image compare additions...",
                 SetUnitalicFactor = "Set un-italic factor...",
+                DiscardTitle = "Discard changes made in OCR?",
+                DiscardText = "Do you want to discard changes made in current OCR session?",
             };
 
             VobSubOcrCharacter = new LanguageStructure.VobSubOcrCharacter

src/Logic/LanguageDeserializer.cs

@@ -5454,6 +5454,12 @@ namespace Nikse.SubtitleEdit.Logic
                 case "VobSubOcr/SetUnitalicFactor":
                     language.VobSubOcr.SetUnitalicFactor = reader.Value;
                     break;
+                case "VobSubOcr/DiscardTitle":
+                    language.VobSubOcr.DiscardTitle = reader.Value;
+                    break;
+                case "VobSubOcr/DiscardText":
+                    language.VobSubOcr.DiscardText = reader.Value;
+                    break;
                 case "VobSubOcrCharacter/Title":
                     language.VobSubOcrCharacter.Title = reader.Value;
                     break;

src/Logic/LanguageStructure.cs

@@ -2227,6 +2227,8 @@
             public string InspectCompareMatchesForCurrentImage { get; set; }
             public string EditLastAdditions { get; set; }
             public string SetUnitalicFactor { get; set; }
+            public string DiscardTitle { get; set; }
+            public string DiscardText { get; set; }
         }
 
         public class VobSubOcrCharacter