{
   cairo's write_png triggers apparent bugs in libpng/libz
   Memcheck:Cond
   obj:/usr/lib/libz.so.1.2.2.2
   obj:/usr/lib/libz.so.1.2.2.2
   fun:deflate
   fun:png_write_finish_row
   fun:png_write_filtered_row
   fun:png_write_find_filter
   fun:png_write_row
   fun:png_write_image
   fun:write_png
 }
{
   cairo's write_png_argb32 triggers apparent bugs in libpng/libz
   Memcheck:Cond
   obj:/usr/lib/libz.so.1.2.2.2
   obj:/usr/lib/libz.so.1.2.2.2
   fun:deflate
   fun:png_write_finish_row
   fun:png_write_filtered_row
   fun:png_write_find_filter
   fun:png_write_row
   fun:png_write_image
   fun:write_png_argb32
 }
