[Bug 38791] New: In server/queue.c, clipping cursor to empty rectangle is off by one pixel (affects "The Long Dark")

https://bugs.winehq.org/show_bug.cgi?id=38791

Bug ID: 38791
           Summary: In server/queue.c, clipping cursor to empty rectangle
                    is off by one pixel (affects "The Long Dark")
           Product: Wine
           Version: 1.7.45
          Hardware: x86
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: wineserver
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Created attachment 51716
  --> https://bugs.winehq.org/attachment.cgi?id=51716
Patch to clip empty rectangles to top left pixel

In server/queue.c functions set_clip_rectangle() and queue_hardware_message(),
the cursor position is clipped to the rectangle desktop->cursor.clip.  However,
if the clipping rectangle has zero width and height, the cursor position is set
to a position offset by (-1,-1) from the top-left corner of the rectangle
instead of *at* the top-left corner.  An empty clipping rectangle is arguably
invalid, but at least one application relies on the cursor being clipped to the
top-left:

The game "The Long Dark" (Steam, Sandbox Alpha v.244) uses such an empty
clipping rectangle while the character is moving.  Because of this bug, mouse
events (including button press and release events with no movement) cause a
shifting of the view down and to the right.

The attached patch fixes the issue.