Reset compilation unit in notification, as it might be damaged.

pkg/analyzer/lib/src/generated/engine.dart

Index: pkg/analyzer/lib/src/generated/engine.dart
diff --git a/pkg/analyzer/lib/src/generated/engine.dart b/pkg/analyzer/lib/src/generated/engine.dart
index 379ada4b5bacbaf96f77572081d0929f70f0fbaf..6de1fb5daf5e73956db825e894b82708fd2581fd 100644
--- a/pkg/analyzer/lib/src/generated/engine.dart
+++ b/pkg/analyzer/lib/src/generated/engine.dart
@@ -5022,7 +5022,10 @@ class AnalysisContextImpl implements InternalAnalysisContext {
         AnalysisPerformanceKind.INCREMENTAL,
         perfCounter,
         'success=$success,context_id=$_id,code_length=${newCode.length}');
+    // if failed, reset compilation unit in notification, it is damaged now
     if (!success) {
+      ChangeNoticeImpl notice = _getNotice(unitSource);
+      notice.compilationUnit = null;

[Brian Wilkerson, 2015/01/12 22:37:02]

Is the compilation unit in the cache marked as invalid? If not, I think this can
produce a loss of information.

       return false;
     }
     // if validation, remember the result, but throw it away