Comp bug - Slip editing a comp to the right creates gap

This case is open with tech support but wanted to share so others can keep an eye out. It's a subtle one that may be able to ruin a project file.
 
Record a track of audio. Create a comp clip in the middle of that track. You've now got three clips.
Grab the left side of the middle clip and slip edit it to the right. The right slide of this middle clip changes. There is now a noticeable gap between the middle and right clips and there has been a new, fourth clip created where you would expect the crossfade to be. This fourth clip is crossfaded with itself.
 
It looks like this may be related to the tempo map. Support says:
" In addition to that, after slicing up a take a bunch of times and then deleting all of the tempo changes caused the clips to become separated, which I imagine is directly related." Most of my work involves lots of comping and at least subtle tempo changes. There is indeed a tricky tempo map on the project where I first experienced this.
 
I've been using the same workflow (comping while tracking) for about a year and very similar for years previous.
I have not seen this happen before this week.
It doesn't happen on a brand new file.
It doesn't appear to be plugin related.
Rolling back the last two or three updates did not make a difference.
Working with support, we could swear that we fixed it somehow but neither of us could figure out what did it. We re-opened the project but could not get it to "fix" again.
Bundle file to support can be opened on their systems and the bug easily reproduced.
 
It's sort-of possible to work around this by dragging the separated clip back to where it's supposed to be but you've also got to deal with that new, incorrectly crossfaded clip that has been created. You can fix it this way but it's hardly a viable option while someone's looking over your shoulder.
 
Any additional info is very much appreciated. Will be working with support and tinkering in the meantime. Will post anything that we come up with.
 
Thanks and cheers
 
 
 
 
 
 
 

How long have you been seeing this?
 
Testing today:
 
New file.
Record a few measures of silence to an audio track.
Place the now marker at the end of the new audio clip to note the end time.
Draw a tempo change into measure 1.
The clip's end time has changed depending on the new tempo.
There is now strange behavior when slipping. Any comp clips now have extra, sometimes tiny, new clips added to the ends. These new clips have incorrect crossfades.
 
You can also:
New project.
Draw some tempo curves.
Record some audio.
Create a comp clip in audio and try slip editing it.
Same issues.
 
Comps are looking at the tempo map to determine how long they're supposed to be relative to the time bar but it's not working out correctly. This means any change to the tempo map can cause immediate (and perhaps very, very subtle) problems to any comps that come later in the project.
 
In short, I can no longer comp in Sonar unless the project tempo is absolutely locked at a steady bpm.
 
 
 
 
 
 
 
 
 

I'm not sure I understand all of the details, and I can't reproduce the first issue you described, but in general, I would suggest the following:
 
If you're going to be changing tempos with recorded audio clips already in the project and you don't want the relationships between clips to change, you must change their Timebase to Absolute. But this means that comp clips will need to be manually moved (as a group) to start at the correct musical time after changing the tempo.
 
Alternatively, you would need to enable Autostretch on all the clips so that their durations follow the tempo changes to prevent gaps/overlaps developing.
 
If you don't want to allow the clips to change durations to follow tempo changes, then I guess you're wanting SONAR to do a little of both: maintain absolute relationships within a group, but follow the change in absolute time of the first clip in the group as it maintains it's musical relationship to the timeline.
 
You seem to be suggesting that this issue is a new phenomenon, but I don't think any version of SONAR has ever been programmed to work that way. And if it were, it would need to be an option, as there are other scenarios in which you wouldn't want it to work that way.
 
 
 

It might depend on exactly what's going on with the tempo changes. When drawing tempo changes, I find that there tend to be way more changes than necessary, and this can cause various issues. Musically, it's not necessary to have tempo changes in between notes, but if you draw lines in the tempo view without having snap enabled, you're likely to end up with dozens of tempo changes every measure.
 
I just did your test, recording an 8th-note riff with the tempo changing from 100 to 164 over 8 measures (1BPM increase at every 8th), and I don't get any weird behavior when splitting up the clip and slip-editing the left edge of a clip in the middle as you described. I also tried it with a more randomly variable tempo map, but keeping the changes no closer together than 8ths, and it was still fine.
 
 

Not notorious enough, apparently. I can't find any obviously similar report.