[PATCH] socket_common: limit garbage workaround to Ruby <= 2.4.1

[Eric Wong <e@80x24.org>]

It looks like Ruby 2.4.1 will have the regression fixed
backported to it:

https://bugs.ruby-lang.org/issues/13299#change-63503

The next releases of Ruby 2.3 and 2.2 may, too; at the
branch maintainer's decision.
---
 lib/mogilefs/socket_common.rb | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/lib/mogilefs/socket_common.rb b/lib/mogilefs/socket_common.rb
index 212f5da..e35ae03 100644
--- a/lib/mogilefs/socket_common.rb
+++ b/lib/mogilefs/socket_common.rb
@@ -59,9 +59,12 @@ def readpartial(size, buf = "", timeout = 5)
   # Workaround for https://bugs.ruby-lang.org/issues/13085
   # (excessive garbage from IO#write)
   # This regression was introduced in Ruby 2.0 (r34847)
-  # and looks like it will be fixed in Ruby 2.5 final.
+  # and looks like it will be fixed in Ruby 2.4.1 and Ruby 2.5
+  # backport request: https://bugs.ruby-lang.org/issues/13299
+  rvn = RUBY_VERSION.split('.'.freeze).map(&:to_i) # "2.4.1" => [ 2, 4, 1 ]
   if defined?(RUBY_ENGINE) && RUBY_ENGINE == 'ruby' &&
-     RUBY_VERSION.to_f >= 2.0 && RUBY_VERSION.to_f <= 2.4
+     rvn[0] >= 2 &&
+     ((rvn[1] == 4 && rvn[2] == 0) || (rvn[1] < 4))
     def write(buf)
       # Blocking TCP writes would error out long before one day,
       # and MogileFS won't allow file creations which take over a day.
-- 
EW