#1788 Malformed loop at start of composition

[musewhirl]

An unintended right click in the ruler area, as opposed to a right click drag, caused what appears to be a zero length, and hence invisible, loop type region at the very start of the composition...except it does not loop. I zoomed to 2000% and can't see any indication of a loop in the ruler area.

I became aware of it because whenever I hit play, regardless of where the playback pointer was located, it returned to the start of the composition played from there. Although an accidental passing click, fortunately loops came to mind, so right clicking again in the ruler area returned normal behavior. An unsuspecting user could have a hard time figuring out why play only starts from the beginning of the composition, because there are no visible clues that a loop exists. Well, not quite true because the the loop icon in the main window and the one in the Transport window do react to the click. In fact, something about the start of the composition in the ruler does change, but you only see that by toggling the click back and forth while watching that area.

Steps to reproduce:

1. Open a new session which has never had a loop activated
2. Place cursor somewhere other than the start of the composition
3. Right click once in the ruler area, where normally you would drag to create a loop
4. A strange behavior is seen (unless it's really intended), but the playback pointer returns to the start on that right click
5. Hit play and after a few measure hit stop
6. If play is hit again, the playback cursor returns to the start and plays from there
7. If the playback pointer is manually moved anywhere other than the start, hitting play will still return the pointer back to start and then play from there

I don't know where the end of the loop is though, and I've not left the composition running long enough to ever see if it return to the start by itself. Besides, when working normally, the length of the loop is obvious in the ruler area.

[Philip Leishman]

Yes this is a malformed loop (from 0 to 0). I have a fix for this.
See codeberg pull request.