downloader.rb: keep linked file newer than cached file

* tool/downloader.rb (Downloader.save_cache): keep linked file
  newer than cached file, so that GNU make triggers when the
  content is updated.  it uses the timestamp of symlink itself
  instead of the target.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67413 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 9 insertions, 3 deletions

diff --git a/tool/downloader.rb b/tool/downloader.rb
index 9c72856484..0386fe273b 100644
--- a/tool/downloader.rb
+++ b/tool/downloader.rb
@@ -285,14 +285,20 @@ class Downloader
   end
 
   def self.save_cache(cache, file, name)
-    if cache and !cache.eql?(file) and !cache.exist?
+    return unless cache or cache.eql?(file)
+    begin
+      st = cache.stat
+    rescue
       begin
         file.rename(cache)
       rescue
-      else
-        link_cache(cache, file, name)
+        return
       end
+    else
+      return unless st.mtime > file.lstat.mtime
+      file.unlink
     end
+    link_cache(cache, file, name)
   end
 
   def self.with_retry(max_times, &block)