anchor.diff:  
       if (shouldGenerateSourceMap) {
         outputSourceMap(mainOutput, lineColumnCollector, '',
  -      compiler.sourceMapUri, compiler.outputUri);
  +          compiler.sourceMapUri, compiler.outputUri);
       }
     }
   
  
positive.code: 
        output.add(generateSourceMapTag(mapUri, partUri));
        output.close();
        outputSourceMap(output, lineColumnCollector, hunkPrefix, mapUri, partUri);
      } else {
        output.close();
      }
  
negative.code:       Uri mapUri, partUri;
        Uri sourceMapUri = compiler.sourceMapUri;
        Uri outputUri = compiler.outputUri;
        String partName = "$hunkPrefix.$partExtension";
        String hunkFileName = "$hunkPrefix.$deferredExtension";
  
        if (sourceMapUri != null) {
          String mapFileName = hunkFileName + ".map";
          List<String> mapSegments = sourceMapUri.pathSegments.toList();
          mapSegments[mapSegments.length - 1] = mapFileName;
          mapUri = compiler.sourceMapUri.replace(pathSegments: mapSegments);
        }
  
        if (outputUri != null) {
          List<String> partSegments = outputUri.pathSegments.toList();
          partSegments[partSegments.length - 1] = hunkFileName;
          partUri = compiler.outputUri.replace(pathSegments: partSegments);
  