Dragging stereo clips bug

[steve]

Observed with Audacity 1.3.14-alpha-Apr 18 2011 (Unicode) on Ubuntu 10.10 and also Audacity 1.3.12 on Windows XP.

In a multi-track project, if a stereo track has only one channel showing in the track panel, and the track is moved by dragging the visible portion with the time shift tool, the other channel will usually also move (correct) but sometimes be left behind (bug).

Probably easier to show in a video than try to describe:
http://www.youtube.com/watch?v=7xf9bYX3H1M

[bgravato]

I could not reproduce that on audacity 1.3.12-beta on mac, neither on 1.3.13-beta (on mac too).

[billw58]

I can reproduce this every time with 1.3.14-alpha April 19 on Mac PPC 10.5.8, following the steps on the video.

The trick is to arrange the window and tracks so when the new track is created, only the left channel is visible. Then it is necessary to click Skip to Start to remove the selection. Then when you drag the new clip in the third track only the left channel portion of it moves. After the move the window scrolls to show the entire third track and you can see the the channels are no longer in sync. At this point you can drag either channel independently. However if you drag one channel until it snaps to the clip in the other channel they will forever after be joined.

I can do this starting with just one stereo track, as long as when the new stereo track is created only the left channel is visible.

-- Bill

[steve]

I've been hunting this one for a while so I'm glad I've finally caught it

I could not reproduce that on audacity 1.3.12-beta on mac, neither on 1.3.13-beta (on mac too).

Gale has come up with some steps that are 100% reproducible on XP (also reproducible on Linux) - if you follow the steps exactly, do you see the bug on Mac?

1 New project, Sync-Lock off
2 Tracks > Add New > Add Stereo Track
3 Generate 30 seconds Tone
4 If needs be, reduce height of project windows so there will not be space to display more than half the LH channel of another stereo track
5 Select 5 - 7s (unknown if the region position/length matters)
6 Edit > Duplicate
7 Click anywhere in the upper track then select Time Shift Tool
8 Hover over what you can see of the duplicated track, drag left and release
9 Only the visible left channel has moved

[billw58]

This is 100% reproducible on Mac with 1.3.8 onwards. Apparently does not exist in 1.3.7.1.

[steve]

Thanks Bill, I've updated the Bugzilla report.

[bgravato]

Yes I was able to reproduce that too on mac in 1.3.13 following Gale steps.