logger.rb: fix next rotate time

* lib/logger.rb (Logger::LogDevice#initialize): calculate next
  rotate time based on the mtime of the last existing file.
  [ruby-dev:49881] [Bug #12948]

Author: Tsukasa Oishi <[email protected]>

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56815 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 5 insertions, 1 deletions

diff --git a/lib/logger.rb b/lib/logger.rb
index e0c93c323c..5dc108f567 100644
--- a/lib/logger.rb
+++ b/lib/logger.rb
@@ -673,7 +673,11 @@ private
         @shift_age = shift_age || 7
         @shift_size = shift_size || 1048576
         @shift_period_suffix = shift_period_suffix || '%Y%m%d'
-        @next_rotate_time = next_rotate_time(Time.now, @shift_age) unless @shift_age.is_a?(Integer)
+
+        unless @shift_age.is_a?(Integer)
+          base_time = @dev.respond_to?(:stat) ? @dev.stat.mtime : Time.now
+          @next_rotate_time = next_rotate_time(base_time, @shift_age)
+        end
       end
     end