Ignore added files in hidden directories.

pkg/analysis_server/lib/src/context_manager.dart

Index: pkg/analysis_server/lib/src/context_manager.dart
diff --git a/pkg/analysis_server/lib/src/context_manager.dart b/pkg/analysis_server/lib/src/context_manager.dart
index f67cfd00b09851d30a55e2b25f077e899dc72d43..f81f5b8eb4b76a95d907dabd6e9211eda5a77e1b 100644
--- a/pkg/analysis_server/lib/src/context_manager.dart
+++ b/pkg/analysis_server/lib/src/context_manager.dart
@@ -1010,7 +1010,7 @@ class ContextManagerImpl implements ContextManager {
       _recomputeFolderDisposition(info);
     }
     // maybe excluded globally
-    if (_isExcluded(path)) {
+    if (_isExcluded(path) || _isContainedInDotFolder(info.folder.path, path)) {
       return;
     }
     // maybe excluded from the context, so other context will handle it
@@ -1146,6 +1146,23 @@ class ContextManagerImpl implements ContextManager {
   }
 
   /**
+   * Determine whether the given [path], when interpreted relative to the
+   * context root [root], contains a folder whose name starts with '.'.
+   */
+  bool _isContainedInDotFolder(String root, String path) {
+    String relativePath =
+        pathContext.relative(pathContext.dirname(path), from: root);
+    for (String pathComponent in pathContext.split(relativePath)) {
+      if (pathComponent.startsWith('.') &&
+          pathComponent != '.' &&
+          pathComponent != '..') {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  /**
    * Returns `true` if the given [path] is excluded by [excludedPaths].
    */
   bool _isExcluded(String path) => _isExcludedBy(excludedPaths, path);