1 files changed, 30 insertions, 1 deletions
diff --git a/spec/ruby/core/io/flush_spec.rb b/spec/ruby/core/io/flush_spec.rb
index c81ff74a69..34cf42c425 100644
--- a/spec/ruby/core/io/flush_spec.rb
+++ b/spec/ruby/core/io/flush_spec.rb
@@ -3,6 +3,35 @@ require_relative 'fixtures/classes'
 
 describe "IO#flush" do
   it "raises IOError on closed stream" do
-    lambda { IOSpecs.closed_io.flush }.should raise_error(IOError)
+    -> { IOSpecs.closed_io.flush }.should raise_error(IOError)
+  end
+
+  describe "on a pipe" do
+    before :each do
+      @r, @w = IO.pipe
+    end
+
+    after :each do
+      @r.close
+      begin
+        @w.close
+      rescue Errno::EPIPE
+      end
+    end
+
+    # [ruby-core:90895] MJIT worker may leave fd open in a forked child.
+    # For instance, MJIT creates a worker before @r.close with fork(), @r.close happens,
+    # and the MJIT worker keeps the pipe open until the worker execve().
+    # TODO: consider acquiring GVL from MJIT worker.
+    guard_not -> { defined?(RubyVM::MJIT) && RubyVM::MJIT.enabled? } do
+      it "raises Errno::EPIPE if sync=false and the read end is closed" do
+        @w.sync = false
+        @w.write "foo"
+        @r.close
+
+        -> { @w.flush }.should raise_error(Errno::EPIPE, /Broken pipe/)
+        -> { @w.close }.should raise_error(Errno::EPIPE, /Broken pipe/)
+      end
+    end
   end
 end