Issue 29109. Resynthesize PrefixElement(s) to fix constants evaluation.

pkg/analyzer/test/src/summary/element_text.dart

 // Copyright (c) 2017, 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.
 
 import 'dart:io';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
@@ skipping 789 matching lines @@
 
     String onlyName(String uri) {
       if (uri.startsWith('file:///')) {
         return uri.substring(uri.lastIndexOf('/') + 1);
       }
       return uri;
     }
 
     ElementLocation location = element.location;
     List<String> components = location.components.toList();
+    if (components.length > 1) {

[Brian Wilkerson, 2017/04/11 18:16:35]

Shouldn't this be ">= 1"? (and similarly on line 813) It probably never matters
because we're probably never passing in a LibraryElement, but...

[scheglov, 2017/04/11 18:27:13]

Yes, I think you're right, it's cleaner to check for only what we really use.
Fixed.

+      components[0] = onlyName(components[0]);
+    }
     if (components.length > 2) {
-      components[0] = onlyName(components[0]);
       components[1] = onlyName(components[1]);
       if (components[0] == components[1]) {
         components.removeAt(0);
       }
     }
     return components.join(';');
   }
 }
 
 class _Replacement {
   final int offset;
   final int end;
   final String text;
   _Replacement(this.offset, this.end, this.text);
 }