Add specs for both cases from jruby#1463.

spec/regression/GH-1463_exceptions_propagate_through_fibers_spec.rb

@@ -0,0 +1,73 @@
+require 'timeout'
+
+describe "A fiber" do
+  describe "that is running while its resuming thread receives an exception" do
+    it "receives that exception" do
+      fiber_exceptions = []
+      thread_exceptions = []
+      100.times do
+        fiber_running = false
+        t = Thread.new do
+          begin
+            f = Fiber.new do
+              fiber_running = true
+              begin
+                sleep 0.2
+              rescue => e
+                fiber_exceptions << e
+              end
+            end
+            f.resume
+          rescue => e
+            thread_exceptions << e
+          end
+        end
+        Thread.pass until fiber_running
+        t.raise StandardError.new
+        t.join
+      end
+
+      fiber_exceptions.size.should == 100
+      fiber_exceptions.each do |ex|
+        ex.should be_kind_of(StandardError)
+      end
+
+      thread_exceptions.should be_empty
+    end
+  end
+
+  describe "that is paused in yield while it receives an exception" do
+    it "raises that exception in its parent thread" do
+      fiber_exceptions = []
+      thread_exceptions = []
+
+      100.times do |i|
+        t = Thread.new do
+          begin
+            f = Fiber.new do
+              begin
+                Timeout.timeout(0.01, StandardError) do
+                  Fiber.yield
+                  end
+              rescue => e
+                fiber_exceptions << e
+              end
+            end
+            f.resume
+            sleep
+          rescue Exception => e
+            thread_exceptions << e
+          end
+        end
+        t.join rescue nil
+      end
+
+      thread_exceptions.size.should == 100
+      thread_exceptions.each do |ex|
+        ex.should be_kind_of(StandardError)
+      end
+
+      fiber_exceptions.should be_empty
+    end
+  end
+end