Comment 17 for bug 1043513

Some random extra debug (from a separate run):
(gdb) up
#3 0x00007f0485ef1af3 in ShadowCopyArea (pSrc=0x7f048ba948f0, pDst=0x7f048c4ca910, pGC=0x7f048c3def70,
    srcx=<optimised out>, srcy=<optimised out>, width=<optimised out>, height=434, dstx=0, dsty=0)
    at ../../../../hw/xfree86/shadowfb/shadow.c:618
618 ../../../../hw/xfree86/shadowfb/shadow.c: No such file or directory.

(gdb) p pDst
$1 = (DrawablePtr) 0x7f048c4ca910
(gdb) p *pDst
$2 = {type = 0 '\000', class = 1 '\001', depth = 32 ' ', bitsPerPixel = 32 ' ', id = 56623110, x = -958,
  y = -716, width = 722, height = 434, pScreen = 0x7f048b738810, serialNumber = 2538}
(gdb) p/x *pDst
$3 = {type = 0x0, class = 0x1, depth = 0x20, bitsPerPixel = 0x20, id = 0x3600006, x = 0xfc42, y = 0xfd34,
  width = 0x2d2, height = 0x1b2, pScreen = 0x7f048b738810, serialNumber = 0x9ea}
(gdb) p pGC
$4 = (GC *) 0x7f048c3def70
(gdb) p pGC->pCompositeClip
$5 = (RegionPtr) 0x7f048c4ca960
(gdb) p *pGC->pCompositeClip
$6 = {extents = {x1 = -958, y1 = -716, x2 = -236, y2 = -282}, data = 0x0}
(gdb) p *(WindowPtr)pDst
$7 = {drawable = {type = 0 '\000', class = 1 '\001', depth = 32 ' ', bitsPerPixel = 32 ' ', id = 56623110,
    x = -958, y = -716, width = 722, height = 434, pScreen = 0x7f048b738810, serialNumber = 2538},
  devPrivates = 0x7f048c4ca9e0, parent = 0x7f048c4c9b80, nextSib = 0x0, prevSib = 0x0,
  firstChild = 0x7f048c4cade0, lastChild = 0x7f048c4cade0, clipList = {extents = {x1 = -958, y1 = -716,
      x2 = -236, y2 = -282}, data = 0x0}, borderClip = {extents = {x1 = -958, y1 = -716, x2 = -236,
      y2 = -282}, data = 0x0}, valdata = 0x0, winSize = {extents = {x1 = -958, y1 = -716, x2 = -236,
      y2 = -282}, data = 0x0}, borderSize = {extents = {x1 = -958, y1 = -716, x2 = -236, y2 = -282},
    data = 0x0}, origin = {x = 0, y = 0}, borderWidth = 0, deliverableEvents = 32799, eventMask = 4423680,
  background = {pixmap = 0xfff2f1f0, pixel = 4294111728}, border = {pixmap = 0x0, pixel = 0},
  backStorage = 0x0, optional = 0x7f048c4caa20, backgroundState = 2, borderIsPixel = 1, cursorIsNone = 1,
  backingStore = 0, saveUnder = 0, DIXsaveUnder = 0, bitGravity = 1, winGravity = 1, overrideRedirect = 0,
  visibility = 0, mapped = 1, realized = 1, viewable = 1, dontPropagate = 0, forcedBS = 0, redirectDraw = 0,
  forcedBG = 0, damagedDescendants = 0, inhibitBGPaint = 0}

(Is the depth/bitsPerPixel correct? I thought this was running at 24bpp - maybe this is some intermediate).
Note how almost every x/y value there is -ve.