htable: fix bug where first entry has hash of 0 or 1.

[ccan] / ccan / htable / test / run-zero-hash-first-entry.c

diff --git a/ccan/htable/test/run-zero-hash-first-entry.c b/ccan/htable/test/run-zero-hash-first-entry.c
new file mode 100644 (file)
index 0000000..fdd1856
--- /dev/null
+++ b/ccan/htable/test/run-zero-hash-first-entry.c
@@ -0,0 +1,61 @@
+#include <ccan/htable/htable.h>
+#include <ccan/htable/htable.c>
+#include <ccan/tap/tap.h>
+#include <stdbool.h>
+
+struct data {
+       size_t key;
+};
+
+/* Hash is simply key itself. */
+static size_t hash(const void *e, void *unused)
+{
+       struct data *d = (struct data *)e;
+
+       return d->key;
+}
+
+static bool eq(const void *e, void *k)
+{
+       struct data *d = (struct data *)e;
+       size_t *key = (size_t *)k;
+
+       return (d->key == *key);
+}
+
+int main(void)
+{
+       struct htable table;
+       struct data *d0, *d1;
+
+       plan_tests(6);
+
+       d1 = malloc(sizeof(struct data));
+       d1->key = 1;
+       d0 = malloc(sizeof(struct data));
+       d0->key = 0;
+
+       htable_init(&table, hash, NULL);
+
+       htable_add(&table, d0->key, d0);
+       htable_add(&table, d1->key, d1);
+
+       ok1(table.elems == 2);
+       ok1(htable_get(&table, 1, eq, &d1->key) == d1);
+       ok1(htable_get(&table, 0, eq, &d0->key) == d0);
+       htable_clear(&table);
+
+       /* Now add in reverse order, should still be OK. */
+       htable_add(&table, d1->key, d1);
+       htable_add(&table, d0->key, d0);
+
+       ok1(table.elems == 2);
+       ok1(htable_get(&table, 1, eq, &d1->key) == d1);
+       ok1(htable_get(&table, 0, eq, &d0->key) == d0);
+       htable_clear(&table);
+
+       free(d0);
+       free(d1);
+       return exit_status();
+}
+