0.8.15.3:

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

diff --git a/src/code/array.lisp b/src/code/array.lisp
index 0a76afa..d300256 100644 (file)
--- a/src/code/array.lisp
+++ b/src/code/array.lisp
@@ -538,7 +538,25 @@
         (error "Axis number ~W is too big; ~S only has ~D dimension~:P."
                axis-number array (%array-rank array)))
        (t
-        (%array-dimension array axis-number))))
+        ;; ANSI sayeth (ADJUST-ARRAY dictionary entry): 
+        ;; 
+        ;;   "If A is displaced to B, the consequences are
+        ;;   unspecified if B is adjusted in such a way that it no
+        ;;   longer has enough elements to satisfy A.
+        ;;
+        ;; In situations where this matters we should be doing a
+        ;; bounds-check, which in turn uses ARRAY-DIMENSION -- so
+        ;; this seems like a good place to signal an error.
+        (multiple-value-bind (target offset) (array-displacement array)
+          (when (and target 
+                     (> (array-total-size array)
+                        (- (array-total-size target) offset)))
+              (error 'displaced-to-array-too-small-error
+                     :format-control "~@<The displaced-to array is too small. ~S ~
+                                      elements after offset required, ~S available.~:@>"
+                     :format-arguments (list (array-total-size array) 
+                                             (- (array-total-size target) offset))))
+          (%array-dimension array axis-number)))))
 
 (defun array-dimensions (array)
   #!+sb-doc