X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fmath%2Finteraction.c;h=4e4134f0ffcceb0b1ac79b5a8e0b583a3924be41;hb=aa2cd68fb42668614f168df3a319e48d009c3cc7;hp=d81eba5095b613231c5deef69d9e68f90c97ff27;hpb=bc414e71fa3378400ef3abf2c247c7f0bbac1b66;p=pspp

diff --git a/src/math/interaction.c b/src/math/interaction.c
index d81eba5095..4e4134f0ff 100644
--- a/src/math/interaction.c
+++ b/src/math/interaction.c
@@ -42,7 +42,6 @@
 */
 
 
-
 struct interaction *
 interaction_create (const struct variable *v)
 {
@@ -57,9 +56,30 @@ interaction_create (const struct variable *v)
   return i;
 }
 
+/* Deep copy an interaction */
+struct interaction *
+interaction_clone (const struct interaction *iact)
+{
+  int v;
+  struct interaction  *i = xmalloc (sizeof *i);
+  i->vars = xcalloc (iact->n_vars, sizeof *i->vars);
+  i->n_vars = iact->n_vars;
+
+  for (v = 0; v < iact->n_vars; ++v)
+    {
+      i->vars[v] = iact->vars[v];
+    }
+
+  return i;
+}
+
+
 void
 interaction_destroy (struct interaction *i)
 {
+  if (NULL == i)
+    return;
+
   free (i->vars);
   free (i);
 }
@@ -152,10 +172,10 @@ interaction_to_string (const struct interaction *iact, struct string *str)
 }
 
 unsigned int
-interaction_case_hash (const struct interaction *iact, const struct ccase *c)
+interaction_case_hash (const struct interaction *iact, const struct ccase *c, unsigned int base)
 {
   int i;
-  size_t hash = 0;
+  size_t hash = base;
   for (i = 0; i < iact->n_vars; ++i)
     {
       const struct variable *var = iact->vars[i];