1.0.4.33: check that context is not a null-alien

[sbcl.git] / src / code / debug-int.lisp

diff --git a/src/code/debug-int.lisp b/src/code/debug-int.lisp
index 3d375e8..fbec1a2 100644 (file)
--- a/src/code/debug-int.lisp
+++ b/src/code/debug-int.lisp
@@ -669,7 +669,8 @@
   ;; nth-interrupt-context, otherwise use the (%caller-frame-and-pc
   ;; vop).
   (let ((context (nth-interrupt-context 0)))
-    (if context
+    (if (and context
+             (not (sb!alien:null-alien context)))
         (compute-calling-frame
          (int-sap (sb!vm:context-register context
                                           sb!vm::cfp-offset))