From c10baabc897210b5f99f4d95ce3ac37cc59aa736 Mon Sep 17 00:00:00 2001
From: "Enrico Weigelt, metux IT consult" <info@metux.net>
Date: Thu, 14 Aug 2025 19:10:03 +0200
Subject: [PATCH] xres: ProcXResQueryClients(): use x_rpcbuf_t

use x_rpcbuf_t for reply payload assembly and byte-swapping.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 Xext/xres.c | 42 ++++++++++--------------------------------
 1 file changed, 10 insertions(+), 32 deletions(-)

diff --git a/Xext/xres.c b/Xext/xres.c
index e00e3fdcd..9426c1eab 100644
--- a/Xext/xres.c
+++ b/Xext/xres.c
@@ -205,56 +205,34 @@ ProcXResQueryClients(ClientPtr client)
 {
     REQUEST_SIZE_MATCH(xXResQueryClientsReq);
 
-    int *current_clients = calloc(currentMaxClients, sizeof(int));
-    if (!current_clients)
-        return BadAlloc;
+    x_rpcbuf_t rpcbuf = { .swapped = client->swapped, .err_clear = TRUE };
 
     int num_clients = 0;
     for (int i = 0; i < currentMaxClients; i++) {
-        if (clients[i]) {
-            if (XaceHookClientAccess(client, clients[i], DixReadAccess) == Success) {
-                current_clients[num_clients] = i;
-                num_clients++;
-            }
+        ClientPtr walkClient = clients[i];
+        if (walkClient &&
+            (XaceHookClientAccess(client, walkClient, DixReadAccess) == Success)) {
+            x_rpcbuf_write_CARD32(&rpcbuf, walkClient->clientAsMask); /* resource_base */
+            x_rpcbuf_write_CARD32(&rpcbuf, RESOURCE_ID_MASK);         /* resource_mask */
+            num_clients++;
         }
     }
 
     xXResQueryClientsReply rep = {
         .type = X_Reply,
         .sequenceNumber = client->sequence,
-        .length = bytes_to_int32(num_clients * sz_xXResClient),
+        .length = x_rpcbuf_wsize_units(&rpcbuf),
         .num_clients = num_clients
     };
+
     if (client->swapped) {
         swaps(&rep.sequenceNumber);
         swapl(&rep.length);
         swapl(&rep.num_clients);
     }
 
-    xXResClient *scratch = NULL;
-
-    if (num_clients) {
-        scratch = calloc(sizeof(xXResClient), num_clients);
-        if (!scratch) {
-            free(current_clients);
-            return BadAlloc;
-        }
-
-        for (int i = 0; i < num_clients; i++) {
-            scratch[i].resource_base = clients[current_clients[i]]->clientAsMask;
-            scratch[i].resource_mask = RESOURCE_ID_MASK;
-
-            if (client->swapped) {
-                swapl(&scratch[i].resource_base);
-                swapl(&scratch[i].resource_mask);
-            }
-        }
-    }
-
     WriteToClient(client, sizeof(xXResQueryClientsReply), &rep);
-    WriteToClient(client, sizeof(xXResClient) * num_clients, scratch);
-    free(current_clients);
-    free(scratch);
+    WriteRpcbufToClient(client, &rpcbuf);
     return Success;
 }