Coding an overlapping range in a directive can result in strange output

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Using the DELTA editor create a directive *EXCLUDE CHARACTERS 1 3 then save.
2. Edit the directive and add a range to the end: 1-4
3. Save.

What is the expected output? What do you see instead?
Expect either an error or the result to be *EXCLUDE CHARACTERS 1-4

Instead you will see:
*EXCLUDE CHARACTERS 1 1-3 3-4

Note that this behaviour is the same in Open DELTA and the original DELTA 
editor.

Original issue reported on code.google.com by [email protected] on 27 Nov 2012 at 2:59