diff --git a/tool/vcs.rb b/tool/vcs.rb
index 629d521320..a7cfa08d52 100644
--- a/tool/vcs.rb
+++ b/tool/vcs.rb
@@ -479,16 +479,18 @@ class VCS
       rev = cmd_read(%W"#{COMMAND} svn info"+[STDERR=>[:child, :out]])[/^Last Changed Rev: (\d+)/, 1]
       com = cmd_read(%W"#{COMMAND} svn find-rev r#{rev}").chomp
 
-      # TODO: dcommit necessary commits only with --add-author-from
-      same = true
-      cmd_pipe([COMMAND, "log", "--format=%ae %ce", "#{com}..@"], "rb") do |r|
-        r.each do |l|
-          same &&= /^(\S+) +\1$/ =~ l
-        end
+      commits = cmd_read([COMMAND, "log", "--reverse", "--format=%H %ae %ce", "#{com}..@"], "rb").split("\n")
+      commits.each_with_index do |l, i|
+        r, a, c = l.split
+        dcommit = [COMMAND, "svn", "dcommit"]
+        dcommit.insert(-2, "-n") if $DEBUG
+        dcommit << "--add-author-from" unless a == c
+        dcommit << r
+        system(*dcommit) or return false
+        system(COMMAND, "rebase") or return false
       end
-      ret = system(COMMAND, "svn", "dcommit", *(["--add-author-from"] unless same))
 
-      if ret and rev
+      if rev
         old = [cmd_read(%W"#{COMMAND} log -1 --format=%H").chomp]
         old << cmd_read(%W"#{COMMAND} svn reset -r#{rev}")[/^r#{rev} = (\h+)/, 1]
         3.times do
@@ -497,7 +499,7 @@ class VCS
           break unless old.include?(cmd_read(%W"#{COMMAND} log -1 --format=%H").chomp)
         end
       end
-      ret
+      true
     end
   end
 end