Bug 357500

I highly recommend you look at the demonstration URL I've included since this a very visual bug and is difficult to explain textually.

After setting a panel's minimum size lower than it's maximum size via the Panel Settings dialogue it proceeds to flicker between it's maximum and minimum size; rapid flickering occurs when plasmoids are present on the panel that have a dynamic size, such as a Flexible Spacer or in my situation/example the Icons-only Task Manager; however when they have a static size such as the Digital Clock or when no plasmoids are present the panel flickers once to it's minimum size and then sticks at it's maximum size.

It should stick at it's minimum size in both instances when there are no widgets or the widgets that are present are not large enough to push the panel to it's maximum size.

Reproducible: Always

Steps to Reproduce:
1. Add an empty panel to any edge of the screen.
2. Set that panel's minimum size lower than it's maximum size.

Actual Results:  
The panel flickered rapidly between it's minimum and maximum size if I added a dynamic size widget like the Icons-only Task Manager. 

The panel flickered once between it's minimum and maximum size then stuck at it's maximum size, if I added a static size widget like the Digital Clock or if I simply didn't add any widgets.

Expected Results:  
The panel should have remained at it's minimum size plus the length of any widgets that exceeded the minimum size but not the maximum size.

This is not the only instance of poor size calculation of plasma widgets in my plasma desktop. For instance, the pager widget when placed on the desktop does not size itself correctly to the workspace squares and has a whole extra segment of background to the right. I'd file that as a extra bug report but I feel the two issues are connected and hopefully the solution to this bug which is the more major one will fix that as well.