Don't try to render cursors with no size
Even if there are no pixels it will still trigger sanity checks
when we start throwing bogus coordinates around.
diff --git a/common/rfb/Cursor.cxx b/common/rfb/Cursor.cxx
index ffbe955..99df82d 100644
--- a/common/rfb/Cursor.cxx
+++ b/common/rfb/Cursor.cxx
@@ -283,6 +283,11 @@
buffer.setPF(format);
buffer.setSize(clippedRect.width(), clippedRect.height());
+ // Bail out early to avoid pestering the framebuffer with
+ // bogus coordinates
+ if (clippedRect.area() == 0)
+ return;
+
data = framebuffer->getBuffer(buffer.getRect(offset), &stride);
buffer.imageRect(buffer.getRect(), data, stride);