coverity#1130421 Improper use of negative value

Change-Id: Iefdd854cb0348b187b95f4a89d52482381c73dfc

basctl/source/basicide/bastypes.cxx

@@ -664,8 +664,9 @@ void CutLines( OUString& rStr, sal_Int32 nStartLine, sal_Int32 nLines, bool bEra
 
     DBG_ASSERTWARNING( nStartPos != -1, "CutLines: Startzeile nicht gefunden!" );
 
-    if ( nStartPos != -1 )
-    {
+    if ( nStartPos == -1 )
+        return;
+
     sal_Int32 nEndPos = nStartPos;
 
     for ( sal_Int32 i = 0; i < nLines; i++ )
@@ -679,7 +680,7 @@ void CutLines( OUString& rStr, sal_Int32 nStartLine, sal_Int32 nLines, bool bEra
     OUString aEndStr = rStr.copy( nEndPos );
     rStr = rStr.copy( 0, nStartPos );
     rStr += aEndStr;
-    }
+
     if ( bEraseTrailingEmptyLines )
     {
         sal_Int32 n = nStartPos;
@@ -692,7 +693,7 @@ void CutLines( OUString& rStr, sal_Int32 nStartLine, sal_Int32 nLines, bool bEra
 
         if ( n > nStartPos )
         {
-            OUString aEndStr = rStr.copy( n );
+            aEndStr = rStr.copy( n );
             rStr = rStr.copy( 0, nStartPos );
             rStr += aEndStr;
         }