Merge fixes from upstream for multiple Xserver issues:

CVE-2025-49175: Out-of-bounds access in X Rendering extension
    (Animated cursors)
CVE-2025-49176: Integer overflow in Big Requests Extension
CVE-2025-49177: Data leak in XFIXES Extension 6
    (XFixesSetClientDisconnectMode)
CVE-2025-49178: Unprocessed client request via bytes to ignore
CVE-2025-49179: Integer overflow in X Record extension
CVE-2025-49180: Integer overflow in RandR extension
    (RRChangeProviderProperty)

xserver/os/io.c

@@ -296,6 +296,10 @@ ReadRequestFromClient(ClientPtr client)
                 needed = get_big_req_len(request, client);
         }
         client->req_len = needed;
+        if (needed > MAXINT >> 2) {
+            /* Check for potential integer overflow */
+            return -(BadLength);
+        }
         needed <<= 2;           /* needed is in bytes now */
     }
     if (gotnow < needed) {
@@ -438,7 +442,7 @@ ReadRequestFromClient(ClientPtr client)
      */
 
     gotnow -= needed;
-    if (!gotnow)
+    if (!gotnow && !oci->ignoreBytes)
         AvailableInput = oc;
     if (move_header) {
         if (client->req_len < bytes_to_int32(sizeof(xBigReq) - sizeof(xReq))) {