Protect against mocking Thread.current

lib/rspec/support.rb

@@ -2,6 +2,9 @@
 
 class Thread
   attr_accessor :__rspec_local_data
+  class << self
+    alias __current_for_rspec current
+  end
 end
 
 module RSpec
@@ -96,7 +99,7 @@ def self.class_of(object)
 
     # A single thread local variable so we don't excessively pollute that namespace.
     def self.thread_local_data
-      Thread.current.__rspec_local_data ||= {}
+      Thread.__current_for_rspec.__rspec_local_data ||= {}
     end
 
     # @api private

spec/rspec/support_spec.rb

@@ -205,6 +205,13 @@ def object.some_method
         end
       end
 
+      it "works when Thread.current is mocked" do
+        expect(Thread).to_not receive(:current)
+
+        RSpec::Support.thread_local_data[:__for_test] = :oh_hai
+        expect(RSpec::Support.thread_local_data[:__for_test]).to eq :oh_hai
+      end
+
       it "works when Thread#thread_variable_get and Thread#thread_variable_set are mocked" do
         expect(Thread.current).to receive(:thread_variable_set).with(:test, true).once.and_return(true)
         expect(Thread.current).to receive(:thread_variable_get).with(:test).once.and_return(true)