+static void insert_pending_discard(xcb_connection_t *c, pending_reply **prev_next, uint64_t seq)
+{
+ pending_reply *pend;
+ pend = malloc(sizeof(*pend));
+ if(!pend)
+ {
+ _xcb_conn_shutdown(c);
+ return;
+ }
+
+ pend->first_request = seq;
+ pend->last_request = seq;
+ pend->workaround = 0;
+ pend->flags = XCB_REQUEST_DISCARD_REPLY;
+ pend->next = *prev_next;
+ *prev_next = pend;
+
+ if(!pend->next)
+ c->in.pending_replies_tail = &pend->next;
+}
+
+static void discard_reply(xcb_connection_t *c, uint64_t request)
+{
+ void *reply;
+ pending_reply **prev_pend;
+
+ /* Free any replies or errors that we've already read. Stop if
+ * xcb_wait_for_reply would block or we've run out of replies. */
+ while(poll_for_reply(c, request, &reply, 0) && reply)
+ free(reply);
+
+ /* If we've proven there are no more responses coming, we're done. */
+ if(XCB_SEQUENCE_COMPARE(request, <=, c->in.request_completed))
+ return;
+
+ /* Walk the list of pending requests. Mark the first match for deletion. */
+ for(prev_pend = &c->in.pending_replies; *prev_pend; prev_pend = &(*prev_pend)->next)
+ {
+ if(XCB_SEQUENCE_COMPARE((*prev_pend)->first_request, >, request))
+ break;
+
+ if((*prev_pend)->first_request == request)
+ {
+ /* Pending reply found. Mark for discard: */
+ (*prev_pend)->flags |= XCB_REQUEST_DISCARD_REPLY;
+ return;
+ }
+ }
+
+ /* Pending reply not found (likely due to _unchecked request). Create one: */
+ insert_pending_discard(c, prev_pend, request);
+}
+
+void xcb_discard_reply(xcb_connection_t *c, unsigned int sequence)
+{
+ if(c->has_error)
+ return;
+
+ /* If an error occurred when issuing the request, fail immediately. */
+ if(!sequence)
+ return;
+
+ pthread_mutex_lock(&c->iolock);
+ discard_reply(c, widen(c, sequence));
+ pthread_mutex_unlock(&c->iolock);
+}
+
+int xcb_poll_for_reply(xcb_connection_t *c, unsigned int request, void **reply, xcb_generic_error_t **error)