Issue 895: NPEs in DeltaAnalyser

compiler/java/com/google/dart/compiler/DeltaAnalyzer.java

Index: compiler/java/com/google/dart/compiler/DeltaAnalyzer.java
diff --git a/compiler/java/com/google/dart/compiler/DeltaAnalyzer.java b/compiler/java/com/google/dart/compiler/DeltaAnalyzer.java
index 6bd802c351dd79406988a2499942f3b9926b36ff..8625698bb3a6cb7a692e6635b070afbfa5313a2a 100644
--- a/compiler/java/com/google/dart/compiler/DeltaAnalyzer.java
+++ b/compiler/java/com/google/dart/compiler/DeltaAnalyzer.java
@@ -87,7 +87,7 @@ class DeltaAnalyzer {
     // Copy all the elements from the old library, except the ones declared in the original source.
     Scope scope = libraryUnit.getElement().getScope();
     for (Element member : enclosingLibrary.getMembers()) {
-      if (member.getNode().getSource() != originalSource) {
+      if (member.getNode() != null && member.getNode().getSource() != originalSource) {
         scope.declareElement(member.getName(), member);
       }
     }