Don't mutate the user metadata :pending wrongly.

In the metadata, `:pending` expresses user intent,
not the result of the running the example. The result
goes in execution_result. So, we should not mutate
this key based on the result of the example.

There was also some missing test coverage that I added here.

Fixes #1376.

lib/rspec/core/example.rb

@@ -212,7 +212,7 @@ def around_each_hooks
       # Used internally to set an exception in an after hook, which
       # captures the exception but doesn't raise it.
       def set_exception(exception, context=nil)
-        if pending?
+        if pending? && !(Pending::PendingExampleFixedError === exception)
           execution_result.pending_exception = exception
         else
           if @exception && context != :dont_print
@@ -321,13 +321,8 @@ def run_after_each
       def verify_mocks
         @example_group_instance.verify_mocks_for_rspec
       rescue Exception => e
-        if execution_result.pending_message
+        if pending?
           execution_result.pending_fixed = false
-          # TODO: should we really change this? In the user metadata,
-          # `:pending` indicates the user intends to make the example
-          # pending, not that it actually was -- that's what the
-          # execution_result is for.
-          metadata[:pending] = true
           @exception = nil
         else
           set_exception(e, :dont_print)

lib/rspec/core/pending.rb

@@ -155,7 +155,6 @@ def self.mark_pending!(example, message_or_bool)
       #
       # @param example [RSpec::Core::Example] the example to mark as fixed
       def self.mark_fixed!(example)
-        example.metadata[:pending] = false
         example.execution_result.pending_fixed = true
       end
     end

spec/rspec/core/pending_example_spec.rb

@@ -23,6 +23,19 @@
       example.run(group.new, double.as_null_object)
       expect(example).to be_pending_with('No reason given')
     end
+
+    it "passes if a mock expectation is not satisifed" do
+      group = RSpec::Core::ExampleGroup.describe('group') do
+        example "example", :pending => "because" do
+          expect(RSpec).to receive(:a_message_in_a_bottle)
+        end
+      end
+
+      example = group.examples.first
+      example.run(group.new, double.as_null_object)
+      expect(example).to be_pending_with('because')
+      expect(example.execution_result.status).to eq('pending')
+    end
   end
 
   context "with no block" do