Re: abort_on_gc in Fgarbage_collect

[Richard Stallman]

Does this version solve all the problems?

DEFUN ("prin1-to-string", Fprin1_to_string, Sprin1_to_string, 1, 2, 0,
       doc: /* Return a string containing the printed representation of OBJECT.
OBJECT can be any Lisp object.  This function outputs quoting characters
when necessary to make output that `read' can handle, whenever possible,
unless the optional second argument NOESCAPE is non-nil.

OBJECT is any of the Lisp data types: a number, a string, a symbol,
a list, a buffer, a window, a frame, etc.

A printed representation of an object is text which describes that object.  */)
     (object, noescape)
     Lisp_Object object, noescape;
{
  Lisp_Object printcharfun;
  /* struct gcpro gcpro1, gcpro2; */
  Lisp_Object save_deactivate_mark;
  int count = specpdl_ptr - specpdl;
  struct buffer *previous;

  specbind (Qinhibit_modification_hooks, Qt);

  {
    PRINTDECLARE;

    /* Save and restore this--we are altering a buffer
       but we don't want to deactivate the mark just for that.
       No need for specbind, since errors deactivate the mark.  */
    save_deactivate_mark = Vdeactivate_mark;
    /* GCPRO2 (object, save_deactivate_mark); */
    abort_on_gc++;

    printcharfun = Vprin1_to_string_buffer;
    PRINTPREPARE;
    print (object, printcharfun, NILP (noescape));
    /* Make Vprin1_to_string_buffer be the default buffer after PRINTFINSH */
    PRINTFINISH;
  }

  previous = current_buffer;
  set_buffer_internal (XBUFFER (Vprin1_to_string_buffer));
  object = Fbuffer_string ();
  if (SBYTES (object) == SCHARS (object))
    STRING_SET_UNIBYTE (object);

  /* Note that this won't make prepare_to_modify_buffer call 
     ask-user-about-supersession-threat because this buffer
     does not visit a file.  */
  Ferase_buffer ();
  set_buffer_internal (previous);

  Vdeactivate_mark = save_deactivate_mark;
  /* UNGCPRO; */

  abort_on_gc--;
  return unbind_to (count, object);
}