Re: GC crashes

[Chong Yidong <cyd@stupidchicken.com>]

The latest bt sent by F.D.F., on closer look, is just plain bizarre:

  #0  initialize_cut_buffers (display=0x8, window=16843009) at xselect.c:2316
  	data = (unsigned char *) 0x820c124 "\213\367\017\b\001"

  #1  0x080ff866 in Fx_rotate_cut_buffers_internal (n=8) at xselect.c:2470
  	window = 73
  	props = {0, 0, 0, 0, 136364324, 138120105, 3220375768, 135779857}
  	display = (Display *) 0x8748060
  	sf = (struct frame *) 0x856d418
  
The relevant line of code in Fx_rotate_cut_buffers_internal is

  initialize_cut_buffers (display, window);

and the code in initialize_cut_buffers is

  static void
  initialize_cut_buffers (display, window)
       Display *display;
       Window window;
  {
    unsigned char *data = (unsigned char *) "";

The values display=0x8, window=16843009 seen in the backtrace probably
mean those haven't been initialized yet.  In any case, there's no
reason for "" to map to 0x820c124 "\213\367\017\b\001".

I don't see any reason for the above code to fail unless it's a
compiler or OS bug.  Ideas welcome.