I have stumbled upon a bug in Wavelab 8.0.3. When running my plugin, the mouseUp function is not being called properly in about 15-20% cases. This happens with my custom buttons (using togglebutton), rotaries and linear sliders.
The way the bug works is: I press on a slider, drag it (moving the mouse up/down and to the side, so that it goes out of bounds) and release the mouse button. Then when I press the mouse button down again (still being out of bounds), the slider reacts and starts dragging. Debugging showed that at the instance the bug appears, the mouseUp() is not being called.
I have also tested the original juce widgets and have found the bug when testing the sliders, though it happens rarely (appeared after: 9, 50, 13, 43 and 17 clicks). When it appears, the bug is visible as the indicator stays in its 'down/clicked' image after the mouse up.
The bug only appears in Wavelab on Mac (on Windows everything works just fine).
Some tech specs:
reproduced in: Wavelab 7 and 8
juce 3.05 and 3.04