Fix Pry.run_command

The problem was that Pry#rep() no longer works on its own, it's
necessary to use Pry#repl() instead. This is because many new API, like
Pry::CodeObject.lookup now get the target binding directly from the _pry_ instance
(Pry#current_context), rather than requiring it to be passed in
separately. This saves us a parameter.

The reason Pry#rep doesnt work with Pry::CodeObject.lookup (and so
show-source/show-doc etc) is that the binding_stack is only set up in
Pry#repl_prologue, and it is the binding_stack (via Pry#current_context)
that is accessed by Pry::CodeObject and pals.

lib/pry/pry_class.rb

@@ -239,7 +239,9 @@ class Pry
 
     output = options[:show_output] ? options[:output] : StringIO.new
 
-    Pry.new(:output => output, :input => StringIO.new(command_string), :commands => options[:commands], :prompt => proc {""}, :hooks => Pry::Hooks.new).rep(options[:context])
+    Pry.new(:output => output, :input => StringIO.new("#{command_string}\nexit-all\n"),
+            :commands => options[:commands],
+            :prompt => proc {""}, :hooks => Pry::Hooks.new).repl(options[:context])
   end
 
   def self.default_editor_for_platform

spec/run_command_spec.rb

@@ -0,0 +1,23 @@
+require 'helper'
+
+describe "Pry.run_command" do
+  before do
+    o = Object.new
+    def o.drum
+      "roken is dodelijk"
+    end
+    @context = Pry.binding_for(o)
+  end
+
+  it 'performs a simple ls' do
+    @context.eval("hokey_pokey = 10")
+    Pry.run_command "ls", :context => @context, :output => out = StringIO.new
+    out.string.should =~ /hokey_pokey/
+  end
+
+  # This is a regression test as 0.9.11 broke this behaviour
+  it 'can perform a show-source' do
+    Pry.run_command "show-source drum", :context => @context, :output => out = StringIO.new
+    out.string.should =~ /roken is dodelijk/
+  end
+end