Comment 6 for bug 492318

The ----( O---- representation will be impossible with mid-marker by two problems:
  * mid-marker are applied in all middle nodes in a path. So if the diagram line has two or more curves we will have two or more symbols.
  * the symbol ----( O---- has no line inside. It's like an neuronium synapsis and a marker can't cut the path.

For cases like that we may create two lines representing the connector: from some object to the middle, and from the middle to the other object, one with a end marker O-- , and another with the start marker --( .

So, i think, we need the option "noncontinuous connector" on the connector tool.