# HG changeset patch
# User Jacek TeMPOraL Złydach <temporal.pl@gmail.com>
# Date 1595027034 -7200
# Node ID 2e90748b1555d86699957d7be1a04ac7d4febe40
# Parent  2288f4ac3903526f1d70859041e29a8085a788b1
Stop passing NIL as :hash-function during hash table construction

At least in SBCL 2.0.6, passing :hash-function NIL to make-hash-table causes an
UNDEFINED-FUNCTION error. Since it's unlikely that any other CL implementation
will have useful behavior for an explicit NIL argument that's different from not
passing it at all, it's better to not pass :hash-function if it's set to NIL.

diff -r 2288f4ac3903 -r 2e90748b1555 src/directed-graph.lisp
--- a/src/directed-graph.lisp	Tue Jan 14 19:11:42 2020 -0500
+++ b/src/directed-graph.lisp	Sat Jul 18 01:03:54 2020 +0200
@@ -2,12 +2,13 @@
 
 ;;;; Utils --------------------------------------------------------------------
 (defun make-hash-table-portably (&key (size 0) test hash-function)
-  (make-hash-table
+  (apply #'make-hash-table
     :test test
     :size size
     ;; Don't explode if the implementation doesn't support :hash-function.
     :allow-other-keys t
-    :hash-function hash-function))
+    (when hash-function
+      (list :hash-function hash-function))))
 
 
 ;;;; Data ---------------------------------------------------------------------