Show{Source,Doc}: refactor assuming definitions from the context

I hope you're pleased now, @banister!

lib/pry/code_object.rb

@@ -91,7 +91,7 @@ class Pry
       # Pry::Method.from_binding when str is nil.
       # Once we refactor Pry::Method.from_str() so it doesnt lookup
       # from bindings, we can get rid of this check
-      return nil if str.to_s.empty?
+      return nil if str.to_s.empty? && super_level.zero?
 
       obj = if str =~ /::(?:\S+)\Z/
         Pry::WrappedModule.from_str(str,target) || Pry::Method.from_str(str, target)

lib/pry/commands/show_info.rb

@@ -155,16 +155,7 @@ class Pry
     end
 
     def obj_name
-      @obj_name ||=
-        if args.empty? && (opts[:super] && opts[:super] > 0)
-          current_method_name
-        else
-          args.join(' ')
-        end
-    end
-
-    def current_method_name
-      _pry_.current_context.eval('::Kernel.__method__').to_s
+      @obj_name ||= args.empty? ? nil : args.join(' ')
     end
 
     def use_line_numbers?