1 files changed, 54 insertions, 0 deletions
diff --git a/spec/ruby/core/fiber/resume_spec.rb b/spec/ruby/core/fiber/resume_spec.rb
new file mode 100644
index 0000000000..3fd3aed8fa
--- /dev/null
+++ b/spec/ruby/core/fiber/resume_spec.rb
@@ -0,0 +1,54 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../../../shared/fiber/resume', __FILE__)
+
+with_feature :fiber do
+  describe "Fiber#resume" do
+    it_behaves_like :fiber_resume, :resume
+  end
+
+  describe "Fiber#resume" do
+    it "returns control to the calling Fiber if called from one" do
+      fiber1 = Fiber.new { :fiber1 }
+      fiber2 = Fiber.new { fiber1.resume; :fiber2 }
+      fiber2.resume.should == :fiber2
+    end
+
+    with_feature :fork do
+      # Redmine #595
+      it "executes the ensure clause" do
+        rd, wr = IO.pipe
+
+        pid = Kernel::fork do
+          rd.close
+          f = Fiber.new do
+            begin
+              Fiber.yield
+            ensure
+              wr.write "executed"
+            end
+          end
+
+          # The apparent issue is that when Fiber.yield executes, control
+          # "leaves" the "ensure block" and so the ensure clause should run. But
+          # control really does NOT leave the ensure block when Fiber.yield
+          # executes. It merely pauses there. To require ensure to run when a
+          # Fiber is suspended then makes ensure-in-a-Fiber-context different
+          # than ensure-in-a-Thread-context and this would be very confusing.
+          f.resume
+
+          # When we execute the second #resume call, the ensure block DOES exit,
+          # the ensure clause runs. This is Ruby behavior as of 2.3.1.
+          f.resume
+
+          exit 0
+        end
+
+        wr.close
+        Process.waitpid pid
+
+        rd.read.should == "executed"
+        rd.close
+      end
+    end
+  end
+end