0.7.6.13:

[sbcl.git] / src / code / numbers.lisp

diff --git a/src/code/numbers.lisp b/src/code/numbers.lisp
index 9eb5d54..18fe19e 100644 (file)
--- a/src/code/numbers.lisp
+++ b/src/code/numbers.lisp
@@ -194,9 +194,13 @@
       (if (minusp den)
          (values (- num) (- den))
          (values num den))
-    (if (eql den 1)
-       num
-       (%make-ratio num den))))
+    (cond
+      ((eql den 0)
+       (error 'division-by-zero
+             :operands (list num den)
+             :operation 'build-ratio))
+      ((eql den 1) num)
+      (t (%make-ratio num den)))))
 
 ;;; Truncate X and Y, but bum the case where Y is 1.
 #!-sb-fluid (declaim (inline maybe-truncate))