4 files changed, 74 insertions, 8 deletions
diff --git a/spec/ruby/core/thread/backtrace_spec.rb b/spec/ruby/core/thread/backtrace_spec.rb
index a20fdee956..532d7a8f4e 100644
--- a/spec/ruby/core/thread/backtrace_spec.rb
+++ b/spec/ruby/core/thread/backtrace_spec.rb
@@ -24,4 +24,12 @@ describe "Thread#backtrace" do
     t.join
     t.backtrace.should == nil
   end
+
+  it "returns an array (which may be empty) immediately after the thread is created" do
+    t = Thread.new { sleep }
+    backtrace = t.backtrace
+    t.kill
+    t.join
+    backtrace.should be_kind_of(Array)
+  end
 end
diff --git a/spec/ruby/core/thread/current_spec.rb b/spec/ruby/core/thread/current_spec.rb
index cc969b71c4..6c4dcfae43 100644
--- a/spec/ruby/core/thread/current_spec.rb
+++ b/spec/ruby/core/thread/current_spec.rb
@@ -12,4 +12,20 @@ describe "Thread.current" do
     t.value.should equal(t)
     Thread.current.should_not equal(t.value)
   end
+
+  it "returns the correct thread in a Fiber" do
+    # This catches a bug where Fibers are running on a thread-pool
+    # and Fibers from a different Ruby Thread reuse the same native thread.
+    # Caching the Ruby Thread based on the native thread is not correct in that case.
+    2.times do
+      t = Thread.new {
+        cur = Thread.current
+        Fiber.new {
+          Thread.current
+        }.resume.should equal cur
+        cur
+      }
+      t.value.should equal t
+    end
+  end
 end
diff --git a/spec/ruby/core/thread/fetch_spec.rb b/spec/ruby/core/thread/fetch_spec.rb
new file mode 100644
index 0000000000..33ac3e0433
--- /dev/null
+++ b/spec/ruby/core/thread/fetch_spec.rb
@@ -0,0 +1,38 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+
+ruby_version_is '2.5' do
+  describe 'Thread#fetch' do
+    describe 'with 2 arguments' do
+      it 'returns the value of the fiber-local variable if value has been assigned' do
+        th = Thread.new { Thread.current[:cat] = 'meow' }
+        th.join
+        th.fetch(:cat, true).should == 'meow'
+      end
+
+      it "returns the default value if fiber-local variable hasn't been assigned" do
+        th = Thread.new {}
+        th.join
+        th.fetch(:cat, true).should == true
+      end
+    end
+
+    describe 'with 1 argument' do
+      it 'raises a KeyError when the Thread does not have a fiber-local variable of the same name' do
+        th = Thread.new {}
+        th.join
+        -> { th.fetch(:cat) }.should raise_error(KeyError)
+      end
+
+      it 'returns the value of the fiber-local variable if value has been assigned' do
+        th = Thread.new { Thread.current[:cat] = 'meow' }
+        th.join
+        th.fetch(:cat).should == 'meow'
+      end
+    end
+
+    it 'raises an ArgumentError when not passed one or two arguments' do
+      -> { Thread.current.fetch() }.should raise_error(ArgumentError)
+      -> { Thread.current.fetch(1, 2, 3) }.should raise_error(ArgumentError)
+    end
+  end
+end
diff --git a/spec/ruby/core/thread/priority_spec.rb b/spec/ruby/core/thread/priority_spec.rb
index b986fb7a0d..40022da80d 100644
--- a/spec/ruby/core/thread/priority_spec.rb
+++ b/spec/ruby/core/thread/priority_spec.rb
@@ -2,13 +2,14 @@ require File.expand_path('../../../spec_helper', __FILE__)
 require File.expand_path('../fixtures/classes', __FILE__)
 
 describe "Thread#priority" do
-  before do
+  before :each do
     @current_priority = Thread.current.priority
     ThreadSpecs.clear_state
     @thread = Thread.new { Thread.pass until ThreadSpecs.state == :exit }
+    Thread.pass until @thread.alive?
   end
 
-  after do
+  after :each do
     ThreadSpecs.state = :exit
     @thread.join
   end
@@ -31,12 +32,14 @@ describe "Thread#priority" do
 end
 
 describe "Thread#priority=" do
-  before do
+  before :each do
     ThreadSpecs.clear_state
-    @thread = Thread.new {}
+    @thread = Thread.new { Thread.pass until ThreadSpecs.state == :exit }
+    Thread.pass until @thread.alive?
   end
 
-  after do
+  after :each do
+    ThreadSpecs.state = :exit
     @thread.join
   end
 
@@ -61,8 +64,9 @@ describe "Thread#priority=" do
   end
 
   it "sets priority even when the thread has died" do
-    @thread.join
-    @thread.priority = 3
-    @thread.priority.should == 3
+    thread = Thread.new {}
+    thread.join
+    thread.priority = 3
+    thread.priority.should == 3
   end
 end