Fixed a possible endless loop in unbalanced translation splitting, fi…

…xed double translation merging. Added alternative text insertion command to chrome extension for cases in which paste command does not work (as it does not on some sites)

OpusCatChromeExtension/extractsource.js

@@ -4,6 +4,8 @@ chrome.runtime.onMessage.addListener(
         var blob = new Blob([request.opusCatTranslationToPaste], {type: 'text/plain'});
         var item = new ClipboardItem({'text/plain': blob});
         navigator.clipboard.write([item]).then(() => document.execCommand('paste'));
+        //If clipboard paste does not work, use insertText
+        //document.execCommand('insertText',false,request.opusCatTranslationToPaste);
     }
   }
 );

OpusCatMTEngine/Marian/MarianProcess.cs

@@ -220,6 +220,11 @@ private List<string> SplitOnMiddle(string preprocessedLine, string splitPattern)
         {
             var lineLength = preprocessedLine.Length;
             var splitterMatches = Regex.Matches(preprocessedLine, Regex.Escape(splitPattern)).Cast<Match>().ToList();
+
+            //Filter out very uneven splits (where one split is less than third of line length), since those won't solve the problem
+            var midpoint = lineLength / 2;
+            splitterMatches = splitterMatches.Where(x => Math.Abs(midpoint - x.Index) < (lineLength / 3)).ToList();
+
             if (splitterMatches.Any())
             {
                 var splitPoint = 

OpusCatMTEngine/Marian/TranslationPair.cs

@@ -227,9 +227,7 @@ private Dictionary<int, List<int>> GenerateDesegmentedAlignment(string sourceSen
         //This joins up two translation pairs, used to produce single output when input 
         // has been segmented into separate sentences
         internal void AppendTranslationPair(TranslationPair translationPart)
-        {
-            this.translation = $"{this.translation} {translationPart.translation}";
-
+        {   
             this.SegmentedAlignmentSourceToTarget = this.JoinAlignments(
                 this.SegmentedAlignmentSourceToTarget, translationPart.SegmentedAlignmentSourceToTarget,
                 this.SegmentedSourceSentence.Length, this.SegmentedTranslation.Length);