vidmode: ProcVidModeGetMonitor(): create reply struct right before send

Move the declaration of the reply struct down to after the payload has
been finally assembled, so we don't need extra payload size compuation
anymore.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>

Xext/vidmode.c

@@ -40,6 +40,7 @@ from Kaleb S. KEITHLEY
 #include "dix/dix_priv.h"
 #include "dix/rpcbuf_priv.h"
 #include "os/log_priv.h"
+#include "os/osdep.h"
 
 #include "misc.h"
 #include "dixstruct.h"
@@ -1228,24 +1229,6 @@ ProcVidModeGetMonitor(ClientPtr client)
     const char *vendorStr = (const char*)pVidMode->GetMonitorValue(pScreen, VIDMODE_MON_VENDOR, 0).ptr;
     const char *modelStr = (const char*)pVidMode->GetMonitorValue(pScreen, VIDMODE_MON_MODEL, 0).ptr;
 
-    const int vendorLength = (vendorStr ? strlen(vendorStr) : 0);
-    const int modelLength = (modelStr ? strlen(modelStr) : 0);
-
-    const int nVendorItems = bytes_to_int32(vendorLength);
-    const int nModelItems = bytes_to_int32(modelLength);
-
-    xXF86VidModeGetMonitorReply rep = {
-        .type = X_Reply,
-        .sequenceNumber = client->sequence,
-        .nhsync = nHsync,
-        .nvsync = nVrefresh,
-        .vendorLength = vendorLength,
-        .modelLength = modelLength,
-        .length = bytes_to_int32(sizeof(xXF86VidModeGetMonitorReply) -
-                                 sizeof(xGenericReply))
-                  + nHsync + nVrefresh + nVendorItems + nModelItems
-    };
-
     x_rpcbuf_t rpcbuf = { .swapped = client->swapped, .err_clear = TRUE };
 
     for (int i = 0; i < nHsync; i++) {
@@ -1268,6 +1251,18 @@ ProcVidModeGetMonitor(ClientPtr client)
     if (rpcbuf.error)
         return BadAlloc;
 
+    xXF86VidModeGetMonitorReply rep = {
+        .type = X_Reply,
+        .sequenceNumber = client->sequence,
+        .nhsync = nHsync,
+        .nvsync = nVrefresh,
+        .vendorLength = x_safe_strlen(vendorStr),
+        .modelLength = x_safe_strlen(modelStr),
+        .length = bytes_to_int32(sizeof(xXF86VidModeGetMonitorReply) -
+                                 sizeof(xGenericReply)) +
+                  x_rpcbuf_wsize_units(&rpcbuf)
+    };
+
     if (client->swapped) {
         swaps(&rep.sequenceNumber);
         swapl(&rep.length);