Fix for NPE if subscribing for errors in a not analyzed file.

R=brianwilkerson@google.com
BUG=

Review URL: https://codereview.chromium.org//398513002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@38238 260f80e4-7a28-3924-810f-c04153c831b5

pkg/analysis_server/lib/src/analysis_server.dart

@@ -470,12 +470,18 @@ class AnalysisServer {
       Set<String> todoFiles = oldFiles != null ? newFiles.difference(oldFiles) : newFiles;
       for (String file in todoFiles) {
         Source source = getSource(file);
+        // prepare context
         AnalysisContext context = getAnalysisContext(file);
+        if (context == null) {
+          continue;
+        }
         // errors
         if (service == AnalysisService.ERRORS) {
           LineInfo lineInfo = context.getLineInfo(source);
-          List<AnalysisError> errors = context.getErrors(source).errors;
-          sendAnalysisNotificationErrors(this, file, lineInfo, errors);
+          if (lineInfo != null) {
+            List<AnalysisError> errors = context.getErrors(source).errors;
+            sendAnalysisNotificationErrors(this, file, lineInfo, errors);
+          }
         }
         // Dart unit notifications.
         if (AnalysisEngine.isDartFileName(file)) {

pkg/analysis_server/test/domain_analysis_test.dart

@@ -325,6 +325,19 @@ void test_setSubscriptions() {
       });
     });
   });
+
+  test('after analysis, no such file', () {
+    AnalysisTestHelper helper = new AnalysisTestHelper();
+    helper.createSingleFileProject('int V = 42;');
+    return helper.waitForOperationsFinished().then((_) {
+      String noFile = '/no-such.file.dart';
+      helper.addAnalysisSubscriptionErrors(noFile);
+      return helper.waitForOperationsFinished().then((_) {
+        var errors = helper.getErrors(noFile);
+        expect(errors, isEmpty);
+      });
+    });
+  });
 }
 
 
@@ -484,6 +497,10 @@ class AnalysisTestHelper {
     handleSuccessfulRequest(request);
   }
 
+  void addAnalysisSubscriptionErrors(String file) {
+    addAnalysisSubscription(AnalysisService.ERRORS, file);
+  }
+
   void addAnalysisSubscriptionHighlights(String file) {
     addAnalysisSubscription(AnalysisService.HIGHLIGHTS, file);
   }