Do more robust parsing of the revision info when creating version numbers.

tools/release/version.dart

 // 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.
 
 /**
  * This file contains functionality for getting dart version numbers using
  * our standard version construction method. Systems that does not include this
  * file should emulate the structure for revision numbers that we have here.
  *
  * The version number of a dart build is constructed as follows:
@@ skipping 101 matching lines @@
     return c.future;
   }
 
   String getExecutableSuffix() {
     if (Platform.operatingSystem == 'windows') {
       return '.bat';
     }
     return '';
   }
 
+  int getRevisionFromSvnInfo(String info) {
+    if (info == null || info == '') return 0;
+    var lines = info.split("\n");
+    RegExp exp = const RegExp(r"Revision: (\d*)");
+    for (var line in lines) {
+      if (exp.hasMatch(line)) {
+        String revisionString = (exp.firstMatch(line).group(1));
+        try {
+          return int.parse(revisionString);
+        } catch(e) {
+          return 0;
+        }
+      }
+    }
+    return 0;
+  }
+
   Future<int> getRevision() {
     if (repositoryType == RepositoryType.UNKNOWN) {
       return new Future.immediate(0);
     }
     var isSvn = repositoryType == RepositoryType.SVN;
     var command = isSvn ? "svn" : "git";
     command = "$command${getExecutableSuffix()}";
     var arguments = isSvn ? ["info"] : ["svn", "info"];
     return Process.run(command, arguments).transform((result) {
       if (result.exitCode != 0) {
         return 0;
       }
-      // If anything goes wrong parsing the revision we simply return 0.
-      try {
-        // Extract the revision. It's located at the 8th line,
-        // 18 characters in.
-        String revisionString = result.stdout.split("\n")[8].substring(18);
-        return int.parse(revisionString);
-      } catch (e) {
-        return 0;
-      }
+      return getRevisionFromSvnInfo(result.stdout);
     });
   }
 
   String getUserName() {
     // TODO(ricow): Don't add this on the buildbot.
     var key = "USER";
     if (Platform.operatingSystem == 'windows') {
       key = "USERNAME";
     }
     if (!Platform.environment.containsKey(key)) return "";
@@ skipping 17 matching lines @@
   static RepositoryType guessType() {
     if (new Directory(".svn").existsSync()) return RepositoryType.SVN;
     if (new Directory(".git").existsSync()) return RepositoryType.GIT;
     return RepositoryType.UNKNOWN;
   }
 
   String toString() => name;
 
   final String name;
 }