Only find package directory for things underneath lib

pkg/docgen/lib/docgen.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /// **docgen** is a tool for creating machine readable representations of Dart
 /// code metadata, including: classes, members, comments and annotations.
 ///
 /// docgen is run on a `.dart` file or a directory containing `.dart` files.
 ///
 ///      $ dart docgen.dart [OPTIONS] [FILE/DIR]
@@ skipping 1405 matching lines @@
   /// If no package could be determined, we return an empty string.
   String _findPackage(LibraryMirror mirror) {
     if (mirror == null) return '';
     if (_hasBeenCheckedForPackage) return packageName;
     _hasBeenCheckedForPackage = true;
     if (mirror.uri.scheme != 'file') return '';
     packageName = _packageName(mirror);
     // Associate the package readme with all the libraries. This is a bit
     // wasteful, but easier than trying to figure out which partial match
     // is best.
-    packageIntro = _packageIntro(_getRootdir(mirror));
+    packageIntro = _packageIntro(_getPackageDirectory(mirror));
     return packageName;
   }
 
   String _packageIntro(packageDir) {
     if (packageDir == null) return null;
     var dir = new Directory(packageDir);
     var files = dir.listSync();
     var readmes = files.where((FileSystemEntity each) => (each is File &&
         each.path.substring(packageDir.length + 1, each.path.length)
           .startsWith('README'))).toList();
     if (readmes.isEmpty) return '';
     // If there are multiples, pick the shortest name.
     readmes.sort((a, b) => a.path.length.compareTo(b.path.length));
     var readme = readmes.first;
     var linkResolver = (name) => Indexable.globalFixReference(name);
     var contents = markdown.markdownToHtml(readme
       .readAsStringSync(), linkResolver: linkResolver,
       inlineSyntaxes: _MARKDOWN_SYNTAXES);
     return contents;
   }
 
   /// Given a LibraryMirror that is a library, return the name of the directory
-  /// holding the package information for that library. If the library is not 
+  /// holding the package information for that library. If the library is not
   /// part of a package, return null.
-  static String _getRootdir(LibraryMirror mirror) {
+  static String _getPackageDirectory(LibraryMirror mirror) {
     var file = mirror.uri.toFilePath();
-    // Any file that's in a package will be in a directory of the form 
+    // Any file that's in a package will be in a directory of the form
     // packagename/lib/.../filename.dart, so we know that a possible
     // package directory is at least in the directory above the one containing
     // [file]
     var directoryAbove = path.dirname(path.dirname(file));
-    return _packageDirectoryFor(directoryAbove);
+    var possiblePackage = _packageDirectoryFor(directoryAbove);
+    // We only want components that are somewhere underneath the lib directory.
+    var subPath = path.relative(file, from: possiblePackage);
+    var subPathComponents = path.split(subPath);
+    if (subPathComponents.isNotEmpty && subPathComponents.first == 'lib') {
+      return possiblePackage;
+    } else {
+      return null;
+    }
   }
 
   /// Read a pubspec and return the library name given a [LibraryMirror].
   static String _packageName(LibraryMirror mirror) {
     if (mirror.uri.scheme != 'file') return '';
-    var rootdir = _getRootdir(mirror);
+    var rootdir = _getPackageDirectory(mirror);
     if (rootdir == null) return '';
     return packageNameFor(rootdir);
   }
 
   /// Recursively walk up from directory name looking for a pubspec. Return
   /// the directory that contains it, or null if none is found.
   static String _packageDirectoryFor(String directoryName) {
     var dir = directoryName;
     while (!_pubspecFor(dir).existsSync()) {
       var newDir = path.dirname(dir);
@@ skipping 778 matching lines @@
         .map((e) => originalMirror.getField(e.simpleName).reflectee)
         .where((e) => e != null)
         .toList();
   }
 
   Map toMap() => {
     'name': Indexable.getDocgenObject(mirror, owningLibrary).docName,
     'parameters': parameters
   };
 }