Issue 24639. Check the correct object for null.

pkg/analyzer/lib/src/task/html_work_manager.dart

Index: pkg/analyzer/lib/src/task/html_work_manager.dart
diff --git a/pkg/analyzer/lib/src/task/html_work_manager.dart b/pkg/analyzer/lib/src/task/html_work_manager.dart
index 218b48ae27e80195fbb9c7fcfea781354751aa59..b0e52bbd658d6b104fd67dfdfbbcec809226da4f 100644
--- a/pkg/analyzer/lib/src/task/html_work_manager.dart
+++ b/pkg/analyzer/lib/src/task/html_work_manager.dart
@@ -231,7 +231,7 @@ class HtmlWorkManager implements WorkManager {
     scriptTargets.forEach(partition.remove);
     for (Source htmlSource in htmlSources) {
       CacheEntry entry = partition.get(htmlSource);
-      if (htmlSource != null) {
+      if (entry != null) {
         entry.setState(HTML_ERRORS, CacheState.INVALID);
         if (invalidateUris) {
           entry.setState(REFERENCED_LIBRARIES, CacheState.INVALID);