hack around caret problem in thebes builds (bug 312106)

gfx/src/thebes/nsThebesRenderingContext.cpp

@@ -657,15 +657,28 @@ nsThebesRenderingContext::FillRect(nscoord aX, nscoord aY, nscoord aWidth, nscoo
     return NS_OK;
 }
 
+
+/**
+ * XXX awful invert rect hack
+ *             idea by mrbkap
+ */
+static unsigned int gInvertRect = 0;
 NS_IMETHODIMP
 nsThebesRenderingContext::InvertRect(const nsRect& aRect)
 {
     gfxContext::GraphicsOperator lastOp = mThebes->CurrentOperator();
 
-    mThebes->SetOperator(gfxContext::OPERATOR_XOR);
+    gfxRGBA newColor(0,0,0,1);
+    if (gInvertRect++ % 2)
+        newColor = gfxRGBA(1,1,1,1);
+    mThebes->Save();
+
+    mThebes->SetColor(newColor);
+    mThebes->SetOperator(gfxContext::OPERATOR_OVER);
     nsresult rv = FillRect(aRect);
     mThebes->SetOperator(lastOp);
 
+    mThebes->Restore();
     return rv;
 }