Description:
In the Impress Presenter Console in the Slides View, "scrolling" with the mouse by dragging the scrollbar switches on MouseUp to the next slide. No matter which position the mouse has, on the mouse up event.


Steps to Reproduce:
1. Open a new Presentation e.g. from Template Focus. Copy and paste slides to get enough slides (>40) so that the Presenter Console will show a scroll bar
2. Start the Presentation with F5
3. Drag the scroll bar

Actual Results:
The presentation switches to the next slide when the mouse up event happens.

Expected Results:
The view has been scrolled and the presented slide hasn't changed.


Reproducible: Always


User Profile Reset: No



Additional Info:
Version: 6.3.3.2
Build ID: 1:6.3.3-0ubuntu0.19.10.1
CPU threads: 12; OS: Linux 5.3; UI render: default; VCL: gtk3; 
Locale: en-US (en_US.UTF-8); UI-Language: en-US
Calc: threaded

OpenGL vendor string: X.Org
OpenGL renderer string: Radeon RX 580 Series (POLARIS10, DRM 3.33.0, 5.3.0-24-generic, LLVM 9.0.0)
OpenGL core profile version string: 4.5 (Core Profile) Mesa 19.2.1
OpenGL core profile shading language version string: 4.50
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile
OpenGL core profile extensions:
OpenGL version string: 4.5 (Compatibility Profile) Mesa 19.2.1
OpenGL shading language version string: 4.50
OpenGL context flags: (none)
OpenGL profile mask: compatibility profile
OpenGL extensions:
OpenGL ES profile version string: OpenGL ES 3.2 Mesa 19.2.1
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.20
OpenGL ES profile extensions:

On another newly install Ubuntu Mate this also occurred.