[bash] Do not append space when path completion is cancelled

Close #990

test/test_go.rb

@@ -1482,6 +1482,19 @@ module CompletionTest
     tmux.send_keys :Enter
   end
 
+  def test_completion_cancel
+    %w[ls cd].each do |cmd|
+      tmux.prepare
+      tmux.send_keys "#{cmd} **", :Tab
+      tmux.until { |lines| lines.item_count > 0 }
+      tmux.send_keys 'C-c'
+      tmux.until { |lines| lines[-1].include?('**') }
+      tmux.send_keys 'xoxo'
+      tmux.until { |lines| lines[-1].include?('**xoxo') }
+      tmux.send_keys 'C-u'
+    end
+  end
+
   def test_dir_completion
     (1..100).each do |idx|
       FileUtils.mkdir_p "/tmp/fzf-test/d#{idx}"