[Bug 46309] New: Winamp with Classic Skin "jumps randomly" when moved

https://bugs.winehq.org/show_bug.cgi?id=46309

Bug ID: 46309
           Summary: Winamp with Classic Skin "jumps randomly" when moved
           Product: Wine
           Version: 4.0-rc2
          Hardware: x86
                OS: Linux
            Status: NEW
          Severity: normal
          Priority: P2
         Component: winex11.drv
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Split from https://bugs.winehq.org/show_bug.cgi?id=15346

When you move Winamp with classic skin, it jumps around randomly. The faster
you move it, the more pronounced this effect is. Eventually it will disappear
because it will touch an edge of the screen (but that has more to do with the
original bug which is a separate problem).

This is probably due to the fact that we use window-relative coordinates and
then translate to screen coordinates ourselves, but those window-relative
aren't synced perfectly with the cursor since Winamp chooses to reposition
itself when moved.

This should be possible to fix by simply using the X-server-supplied
root-relative coordinates and we can even get rid of the redundant
transformations after that, as we have them already in screen coordinates (with
slight translation), which should even simplify the code on top of it...