Handle parse exceptions on format save action

org.scala-ide.sdt.core/src/scala/tools/eclipse/formatter/ScalaFormatterCleanUpProvider.scala

@@ -1,22 +1,25 @@
 package scala.tools.eclipse.formatter
 
 import org.eclipse.jdt.internal.corext.fix.CodeFormatFix
-import scala.tools.eclipse.contribution.weaving.jdt.ui.javaeditor.formatter.IFormatterCleanUpProvider
 import org.eclipse.jdt.core.ICompilationUnit
-import org.eclipse.jface.text.{ Document, TextUtilities };
+import org.eclipse.jdt.core.refactoring.CompilationUnitChange
 import org.eclipse.jdt.ui.cleanup.ICleanUpFix
-import scalariform.formatter.ScalaFormatter
+import org.eclipse.jface.text.{ Document, TextUtilities }
 import org.eclipse.text.edits.{ TextEdit => JFaceTextEdit, _ }
+import scalariform.formatter.ScalaFormatter
+import scalariform.parser.ScalaParserException
 import scalariform.utils.TextEdit
-import org.eclipse.jdt.core.refactoring.CompilationUnitChange
+import scala.tools.eclipse.contribution.weaving.jdt.ui.javaeditor.formatter.IFormatterCleanUpProvider
+import org.eclipse.jdt.internal.ui.javaeditor.DocumentAdapter
 
 class ScalaFormatterCleanUpProvider extends IFormatterCleanUpProvider {
 
   def createCleanUp(cu: ICompilationUnit): ICleanUpFix = {
-    val contents = cu.getBuffer.getContents
-    val document = new Document(contents)
+    val document = cu.getBuffer.asInstanceOf[DocumentAdapter].getDocument
     val lineDelimiter = TextUtilities.getDefaultLineDelimiter(document)
-    val edits = ScalaFormatter.formatAsEdits(cu.getSource, FormatterPreferencePage.getPreferences, Some(lineDelimiter))
+    val edits =
+      try ScalaFormatter.formatAsEdits(cu.getSource, FormatterPreferencePage.getPreferences, Some(lineDelimiter))
+      catch { case e: ScalaParserException => return null }
     val resultEdit = new MultiTextEdit
     for (TextEdit(start, length, replacement) <- edits)
       resultEdit.addChild(new ReplaceEdit(start, length, replacement))