Accept bignums unambiguously in the syntax for object labels, lread.c. src/ChangeLog addition: 2011-12-03 Aidan Kehoe <kehoea@parhasard.net> * lread.c (read1): Don't wrap when reading expressions that use bignums as object labels, that can lead to ambiguity and it's not actually that hard to use parse_integer() to avoid it. tests/ChangeLog addition: 2011-12-03 Aidan Kehoe <kehoea@parhasard.net> * automated/lisp-reader-tests.el: Check that integer object labels (using the #N=... syntax) treat bignums as such, rather than as fixnums that have wrapped.

--- a/tests/automated/lisp-reader-tests.el	Tue Nov 29 16:19:53 2011 +0100
+++ b/tests/automated/lisp-reader-tests.el	Sat Dec 03 15:13:55 2011 +0000
@@ -150,3 +150,8 @@
               (car (get-range-table #x1001 deserialized-range-table)))
           "checking the lisp reader handles deserialization identity, mixed"))
 
+(when (featurep 'bignum)
+  (Assert (null (list-length (read (format "#%d=(1 #1=(5) 3 4 . #%d#)"
+					   (+ most-positive-fixnum 2)
+					   (+ most-positive-fixnum 2)))))
+	  "checking bignum object labels don't wrap on reading"))