fix problems coming from moving first production by inserting explicit

start symbol

CupPlugin/src/de/tum/in/www2/cupplugin/views/ReduceReduceReorder.java

@@ -7,6 +7,7 @@ import java.util.List;
 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.IDocument;
 
+import de.in.tum.www2.cup.ast.NonTerminal;
 import de.in.tum.www2.cup.ast.ParserResult;
 import de.in.tum.www2.cup.ast.Production;
 import de.in.tum.www2.cup.ast.ProductionRight;
@@ -18,6 +19,8 @@ public class ReduceReduceReorder {
 	String textToAppend;
 	boolean flagPresent;
 	private List<RangeToRemove> rangesToRemove;
+	private boolean movedFirstProd = false;
+	private String firstNonTermWas = "";
 	
 	private class RangeToRemove implements Comparable<RangeToRemove>{
 		int start;
@@ -52,6 +55,12 @@ public class ReduceReduceReorder {
 		
 		if(p.getRightHandSides().size() == 1){
 			try {
+				
+				if(Model.getInstanceForDocument(document).getAstModel().productions.indexOf(p) == 0){
+					movedFirstProd = true;
+					firstNonTermWas = p.getName().name;
+				}
+				
 				String pString = document.get(p.getBegin().getOffsetFromStart(), 
 						p.getEnd().getOffsetFromStart() - p.getBegin().getOffsetFromStart());
 			
@@ -131,6 +140,7 @@ public class ReduceReduceReorder {
 	public void apply() throws BadLocationException{
 		insert();
 		removeAllOldItems();
+		fixStart();
 	}
 	
 	private void insert() throws BadLocationException{
@@ -142,6 +152,23 @@ public class ReduceReduceReorder {
 		document.replace(positionForProd, 0, textToAppend);
 	}
 	
+	/**
+	 * Add the start with statement if the first production was moved and no start with statement was given
+	 * Otherwise the start symbol defaults to the first production that is usually different
+	 * @throws BadLocationException
+	 */
+	private void fixStart() throws BadLocationException{
+		if(movedFirstProd){
+			ParserResult r = Model.getInstanceForDocument(document).getAstModel();
+			if(r.startWith == null){
+				String toInsert = "// Inserted by CUP Eclipse plugin after moving rules\nstart with " + firstNonTermWas + "; \n\n\n";
+				
+				int pos = r.productions.get(0).getRange().getBegin().getOffsetFromStart();
+				document.replace(pos, 0, toInsert);
+			}
+		}
+	}
+	
 	private void removeAllOldItems() throws BadLocationException{
 		Collections.sort(rangesToRemove);
 		Collections.reverse(rangesToRemove);