bugfix: use proper hashing for cptr.

Since cptr objects are equal if their handles are equal, they
must have a hashing function over the handle rather than over
their own address.

* lib.c (cobj_handle_hash_op): New function.
(cptr_ops): Use cobj_handle_hash_op instead of
cobj_eq_hash_op.

* lib.h (cobj_handle_hash_op): Declared.

* sysif.c (cptr_dl_ops): Use cobj_handle_hash_op instead of
cobj_eq_hash_op.

3 files changed, 9 insertions, 2 deletions

diff --git a/lib.c b/lib.c
index 03915d08..6939f817 100644
--- a/lib.c
+++ b/lib.c
@@ -7389,12 +7389,18 @@ val cobj_equal_handle_op(val left, val right)
   return (left->co.handle == right->co.handle) ? t : nil;
 }
 
+cnum cobj_handle_hash_op(val obj, int *count)
+{
+  mem_t *handle = obj->co.handle;
+  return cobj_eq_hash_op(coerce(val, handle), count);
+}
+
 static struct cobj_ops cptr_ops = {
   cobj_equal_handle_op,
   cobj_print_op,
   cobj_destroy_stub_op,
   cobj_mark_op,
-  cobj_eq_hash_op
+  cobj_handle_hash_op
 };
 
 val cptr(mem_t *ptr)
diff --git a/lib.h b/lib.h
index f1274bf1..301e46c4 100644
--- a/lib.h
+++ b/lib.h
@@ -258,6 +258,7 @@ void cobj_destroy_stub_op(val);
 void cobj_destroy_free_op(val);
 void cobj_mark_op(val);
 cnum cobj_eq_hash_op(val, int *);
+cnum cobj_handle_hash_op(val, int *);
 
 struct env {
   obj_common;
diff --git a/sysif.c b/sysif.c
index e4d6de88..78dcda6c 100644
--- a/sysif.c
+++ b/sysif.c
@@ -1470,7 +1470,7 @@ static struct cobj_ops cptr_dl_ops = {
   cobj_print_op,
   cptr_dl_destroy_op,
   cobj_mark_op,
-  cobj_eq_hash_op
+  cobj_handle_hash_op
 };
 
 static val dlopen_wrap(val name, val flags)