Prefix io part uri's with 'dart:io/'.

runtime/bin/dartutils.cc

 // Copyright (c) 2012, 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.
 
 #include "bin/dartutils.h"
 
 #include "include/dart_api.h"
 #include "include/dart_native_api.h"
 
 #include "platform/assert.h"
@@ skipping 505 matching lines @@
                       " on the stand-alone VM.\n", url_string);
     } else {
       ASSERT(tag == Dart_kSourceTag);
       return NewError("Unable to load source '%s' ", url_string);
     }
   }
 
   // Handle 'part' of IO library.
   if (is_io_library) {
     if (tag == Dart_kSourceTag) {
+      // Prepend the library URI to form a unique script URI for the part.
+      intptr_t len = snprintf(NULL, 0, "%s/%s", library_url_string, url_string);
+      char* part_uri = reinterpret_cast<char*>(malloc(len + 1));
+      snprintf(part_uri, len + 1, "%s/%s", library_url_string, url_string);
+      Dart_Handle part_uri_obj = DartUtils::NewString(part_uri);
+      free(part_uri);
       return Dart_LoadSource(
-          library, url, Builtin::PartSource(Builtin::kIOLibrary, url_string));
+          library,
+          part_uri_obj,
+          Builtin::PartSource(Builtin::kIOLibrary, url_string));
     } else {
       ASSERT(tag == Dart_kImportTag);
       return NewError("Unable to import '%s' ", url_string);
     }
   }
 
   Dart_Handle builtin_lib =
       Builtin::LoadAndCheckLibrary(Builtin::kBuiltinLibrary);
   if (DartUtils::IsDartExtensionSchemeURL(url_string)) {
     // Load a native code shared library to use in a native extension
@@ skipping 574 matching lines @@
       new CObjectString(CObject::NewString(os_error->message()));
   CObjectArray* result = new CObjectArray(CObject::NewArray(3));
   result->SetAt(0, new CObjectInt32(CObject::NewInt32(kOSError)));
   result->SetAt(1, new CObjectInt32(CObject::NewInt32(os_error->code())));
   result->SetAt(2, error_message);
   return result;
 }
 
 }  // namespace bin
 }  // namespace dart