* hash.c (remhash): Rewrote buggy function.

It was decrementing the hash count without checking that
something was deleted from the chain. The deletion was done
incorrectly, without regard for the kind of comparison fucntion
used by the hash table.

1 files changed, 9 insertions, 3 deletions

diff --git a/hash.c b/hash.c
index 32868569..d052c637 100644
--- a/hash.c
+++ b/hash.c
@@ -342,9 +342,15 @@ val remhash(val hash, val key)
 {
   struct hash *h = (struct hash *) cobj_handle(hash, hash_s);
   val *pchain = vecref_l(h->table, num(h->hash_fun(key) % h->modulus));
-  *pchain = alist_remove1(*pchain, key);
-  h->count--;
-  bug_unless (h->count >= 0);
+  val existing = h->assoc_fun(key, *pchain);
+
+  if (existing) {
+    val loc = memq(existing, *pchain);
+    *pchain = nappend2(ldiff(*pchain, loc), cdr(loc));
+    h->count--;
+    bug_unless (h->count >= 0);
+  }
+
   return nil;
 }