Function with_proj_key

src/cypher/cypher.c:4059–4074

Build a key from a projected vbinding's value tuple (all WITH output items), * used to detect duplicate rows for WITH DISTINCT (#238). */

/* Build a key from a projected vbinding's value tuple (all WITH output items),
 * used to detect duplicate rows for WITH DISTINCT (#238). */
static void with_proj_key(cbm_return_clause_t *wc, binding_t *b, char *key, size_t key_sz) {
    int kl = 0;
    key[0] = '\0';
    char name_buf[CBM_SZ_256];
    for (int ci = 0; ci < wc->count; ci++) {
        const char *alias = resolve_item_alias(&wc->items[ci], name_buf, sizeof(name_buf));
        const char *v = binding_get_virtual(b, alias, NULL);
        int w = snprintf(key + kl, (kl < (int)key_sz) ? key_sz - (size_t)kl : 0, "%s|", v ? v : "");
        if (w > 0) {
            kl += w;
        }
        if (kl >= (int)key_sz) {
            break; /* buffer full */
        }
    }
}

/* Apply WITH DISTINCT: drop projected rows whose value tuple duplicates an
 * earlier one, keeping first occurrence (#238 — previously silently ignored). */