Bug 1191

Created attachment 734 [details] [review]
proposed patch for fixing composite exposures

The patch that I proposed to the xorg ML some days ago.

Comment on attachment 734 [details] [review]
proposed patch for fixing composite exposures

This patch is toast, from the disk crash I'd guess.  Reattach?

Created attachment 4202 [details] [review]
Patch that fixes the exposure bugs

Here it is... anyway this patch is only an underflow check. anholt or keipth,
tell me if this helps:)

Moving to xorg

is this still relevant?  The patches are a tad old and probably need to be 
rebased.  If you are still having a problem, I suggest you update your patch 
and send it to xorg-devel for review by a wider audience.  If it's not a 
problem (or we don't hear back in a while), I'm just going to close this bug 
since kdrive will probably be gone in the next year or two anyway.

The patch is gzipped, though apparently bz can't figure that out. It looks like this:

===
--- xserver/mi/mivaltree.c      2004-08-18 21:43:15.000000000 +0000
+++ xserver-new/mi/mivaltree.c  2004-08-18 21:47:14.000000000 +0000
@@ -275,6 +275,15 @@
        if (miSetRedirectBorderClipProc)
            (*miSetRedirectBorderClipProc) (pParent, universe);
        REGION_COPY(pScreen, universe, &pParent->borderSize);
+
+       /* 
+        * Check that universe does not contain negative values
+        * so that the result of miComputeClip stays valid.
+        */
+       if (universe->extents.x1 < 0) universe->extents.x1 = 0;
+       if (universe->extents.y1 < 0) universe->extents.y1 = 0;
+       if (universe->extents.x2 < 0) universe->extents.x2 = 0;
+       if (universe->extents.y2 < 0) universe->extents.y2 = 0;
     }
 #endif
 
--- xserver/composite/compwindow.c      2004-08-18 21:43:03.000000000 +0000
+++ xserver-new/composite/compwindow.c  2004-08-18 21:42:24.000000000 +0000
@@ -586,14 +586,17 @@
 {
     CompWindowPtr   cw = GetCompWindow (pWin);
     RegionRec      damage;
+    int             translatex = pWin->drawable.x - cw->borderClipX;
+    int             translatey = pWin->drawable.y - cw->borderClipY;
 
     REGION_INIT (pScreen, &damage, NullBox, 0);
     /*
      * Align old border clip with new border clip
+     * Avoid negative values
      */
     REGION_TRANSLATE (pScreen, &cw->borderClip,
-                     pWin->drawable.x - cw->borderClipX,
-                     pWin->drawable.y - cw->borderClipY);
+                     (translatex>0) ? translatex : 0,
+                     (translatey>0) ? translatey : 0);
     /*
      * Compute newly visible portion of window for repaint
      */
@@ -604,11 +607,11 @@
     DamageDamageRegion (&pWin->drawable, &damage);
     REGION_UNINIT (pScreen, &damage);
     /*
-     * Save the new border clip region
+     * Save the new border clip region. Avoid negative values
      */
     REGION_COPY (pScreen, &cw->borderClip, pRegion);
-    cw->borderClipX = pWin->drawable.x;
-    cw->borderClipY = pWin->drawable.y;
+    cw->borderClipX = (pWin->drawable.x > 0) ? pWin->drawable.x : 0;
+    cw->borderClipY = (pWin->drawable.y > 0) ? pWin->drawable.y : 0;
 }
 
 RegionPtr
===

Obviously that doesn't apply to current git. More importantly the fix is wrong, regions are allowed to have negative coordinates. Presumably some other code was failing to clip to the root window's storage correctly.