Message created at the wrong position in certain cases

[Matthias Schoettle]

There is at least one case where when creating a message between two existing lifelines that the retrieved index is wrong (too low).

Consider the following example:

The message will be created above yield() instead of below it.

This is because only the fragment before the to lifeline is considered, which is above. Calling getIndexAfter(...) will not find messages below if the fragment is not a send event.

Since getIndexAfter(...) was substantially improved recently I suggest only using the from lifeline to find the index after.

[Matthias Schoettle]

Resolves #248: Changes the behaviour when finding the index in the model of where to create the message at by always using the from lifeline.

→ <<cset c5cc0ed99b39>>