Comment 2 for bug 699309

Still present in git HEAD as of 2012-01-22.

I have my copy of PCB configured so that its buttons are consistent with GIMP and Inkscape - scroll wheel to zoom, middle-click-and-drag to pan. So for me, it's caused by a simple corner case where it is easy to accidentally roll the scroll wheel a click or two while it is held down for the middle-click-and-drag action.

As before, this applies to the GTK version; not sure if it affects Lesstif.

Test case:

Start PCB, but do not load a layout file - just leave the blank, default layout in place. Middle click and drag to pan. Be sure you mash the button down firmly; you don't want to let it go unintentionally here. While continuing to hold the button down, move the pointer onto the sidebar on the left. Position it between the tool cluster and the layer buttons. Then, while *still holding* the third/middle-click button, roll the scroll wheel a few clicks in either direction.

What happens:

The program gets stuck in this weird pan-and-zoom-only mode as soon as it sees the scroll wheel moving, with only one way out: Hit the Close Window button and let PCB save your layout on the way down, if necessary.

What should happen:

The mouse should, with no exceptions, continue to pan no matter where it moves to - even it ends up on a different monitor - and leave that mode entirely and absolutely when the user lets go of the button. The program should hold focus until the user releases the button (at which point, the program should pass focus back to whatever the window manager says should have it).