Fix message about status entries that need manual splitting.

tools/migration/lib/src/migrate_statuses.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 'package:path/path.dart' as p;
 
 import 'editable_status_file.dart';
 import 'fork.dart';
 import 'io.dart';
 import 'log.dart';
 import 'test_directories.dart';
 
 /// Migrates the status file entries that match [files].
 void migrateStatusEntries(List<Fork> files, Map<String, List<String>> todos) {
   var entriesToMove = new EntrySet();
 
   _collectEntries(files, entriesToMove, isOne: true);
   _collectEntries(files, entriesToMove, isOne: false);
 
   for (var statusFile in entriesToMove.statusFiles) {
     var sections = entriesToMove.sections(statusFile);
     _addEntries(statusFile, sections);
   }
 
   // If any entries need manual splitting, let the user know.
-  for (var dir in entriesToMove._todoHeaders.keys) {
-    var destination = "$dir.status";
-    var headers = entriesToMove._todoHeaders[dir];
+  for (var statusFile in entriesToMove._todoHeaders.keys) {
+    var headers = entriesToMove._todoHeaders[statusFile];
     var splits = headers.map((header) {
-      var files =
-          filesForHeader(header).map((file) => bold("${dir}_$file")).join(", ");
-      return "Need to manually split status file section in ${bold(destination)}"
-          " across files $files:\n    $header";
+      var files = filesForHeader(header).map((file) => bold(file)).join(", ");
+      return "Manually split status file section across $files status files:\n"
+          "    $header";
     }).toList();
 
-    if (splits.isNotEmpty) todos[destination] = splits;
+    if (splits.isNotEmpty) todos[statusFile] = splits;
   }
 }
 
 /// Given the header for a status file section, looks at the condition
 /// expression to determine which status files it should go in.
 Set<String> filesForHeader(String header) {
   // Figure out which status file it goes into.
   var result = new Set<String>();
 
   // The various compilers are roughly separate products.
@@ skipping 38 matching lines @@
 
   final _todoHeaders = <String, Set<String>>{};
 
   Iterable<String> get statusFiles => _files.keys;
 
   /// Attempts to add the [entry] under [header] in a status file in [fromDir]
   /// to this EntrySet.
   ///
   /// Returns true if successful or false if the header's condition doesn't fit
   /// into a single status file and needs to be manually split by the user.
-  bool add(String fromDir, String header, String entry) {
+  bool add(String fromFile, String fromDir, String header, String entry) {
     var toDir = toTwoDirectory(fromDir);
 
     // Figure out which status file it goes into.
     var possibleFiles = filesForHeader(header);
     var destination = "$toDir.status";
 
     if (possibleFiles.length > 1) {
       // The condition matches multiple files, so the user is going to have to
       // manually split it up into multiple sections first.
       // TODO(rnystrom): Would be good to automate this, though it requires
       // being able to work with condition expressions directly.
-      _todoHeaders.putIfAbsent(toDir, () => new Set()).add(header);
+      var statusRelative = p.relative(fromFile, from: testRoot);
+      _todoHeaders.putIfAbsent(statusRelative, () => new Set()).add(header);
       return false;
     }
 
     // If the condition places it directly into one file, put it there.
     if (possibleFiles.length == 1) {
       destination = "${toDir}_${possibleFiles.single}.status";
     }
 
     var sections = _files.putIfAbsent(p.join(toDir, destination), () => {});
 
@@ skipping 33 matching lines @@
             // migrated, or a multitest within that. In both cases, the entry
             // path will begin with the full path of the file. We don't migrate
             // directory or glob patterns because those may also match other
             // files that have not been migrated yet.
             // TODO(rnystrom): It would be good to detect when a glob matches
             // a migrated file and let the user know that they may need to
             // manually handle it.
             if (!entryPath.startsWith(filePath)) continue;
 
             // Add it to the 2.0 one.
-            if (entriesToMove.add(fromDir, editable.lineAt(section.lineNumber),
+            if (entriesToMove.add(
+                path,
+                fromDir,
+                editable.lineAt(section.lineNumber),
                 editable.lineAt(entry.lineNumber))) {
               // Remove it from the original status file.
               deleteLines.add(entry.lineNumber - 1);
             }
           }
         }
       }
 
       // TODO(rnystrom): If all of the entries are deleted from a section, it
       // would be nice to delete the section header too.
@@ skipping 27 matching lines @@
         break;
       }
     }
 
     if (!found) {
       // This section doesn't exist in the status file, so add it.
       editable.append(header, entries[header]);
     }
   }
 }