[Emacs-diffs] Changes to emacs/src/print.c

[Chong Yidong]

Index: emacs/src/print.c
diff -u emacs/src/print.c:1.216 emacs/src/print.c:1.217
--- emacs/src/print.c:1.216     Sat Dec 17 15:46:16 2005
+++ emacs/src/print.c   Sat Dec 17 15:51:00 2005
@@ -1313,8 +1313,14 @@
 
   /* Give up if we go so deep that print_object will get an error.  */
   /* See similar code in print_object.  */
-  if (print_depth >= PRINT_CIRCLE)
-    error ("Apparently circular structure being printed");
+  /* Because print_preprocess "follows" nested lists in a slightly
+     different order from print_object, there is a risk of giving up
+     too soon.  In that case, a deeply nested circular list may cause
+     print_object to loop.  Using 3 * PRINT_CIRCLE should make this
+     possibility negligible, but at some point someone will have to
+     sit down and do a more careful analysis. -- cyd */
+  if (print_depth >= 3 * PRINT_CIRCLE)
+    return;
 
   /* Avoid infinite recursion for circular nested structure
      in the case where Vprint_circle is nil.  */