From 4cf62d5eeafcd8bfb67692aed4e429fc07255bf1 Mon Sep 17 00:00:00 2001
From: "Enrico Weigelt, metux IT consult" <info@metux.net>
Date: Thu, 25 Jul 2024 17:19:42 +0200
Subject: [PATCH] (submit/cleanup-xkb) xkb: split XkbSendNames()

This function is a funny beast: it assembles and writes out an xkbGetNamesReply,
called in two different cases, ProcXkbGetNames() as well as ProcXkbGetKbdByName().
In the latter case the whole reply is contained in another one. That's the reason
why it's payload size is computed separately - the caller must know that in order
to set up the container's reply size correctly.

As preparation for upcoming simplifications of the reply send path, splitting off
this function into pieces: XkbAssembleNames() just assembles the reply payload,
while it's callers now responsible for preparing the request header and writing
out both pieces.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 xkb/xkb.c | 65 ++++++++++++++++++++++++++++++++++---------------------
 1 file changed, 40 insertions(+), 25 deletions(-)

diff --git a/xkb/xkb.c b/xkb/xkb.c
index 31d19a6622..9fa1ec4990 100644
--- a/xkb/xkb.c
+++ b/xkb/xkb.c
@@ -3783,23 +3783,14 @@ XkbComputeGetNamesReplySize(XkbDescPtr xkb, xkbGetNamesReply * rep)
         desc += sizeof(CARD32); \
     } while (0)
 
-static int
-XkbSendNames(ClientPtr client, XkbDescPtr xkb, xkbGetNamesReply rep)
+static void
+XkbAssembleNames(ClientPtr client, XkbDescPtr xkb, xkbGetNamesReply rep, char *buf)
 {
-    register unsigned i, length, which;
-
-    length = rep.length * 4;
+    register unsigned i, which;
     which = rep.which;
-    if (client->swapped) {
-        swaps(&rep.sequenceNumber);
-        swapl(&rep.length);
-        swapl(&rep.which);
-        swaps(&rep.virtualMods);
-        swapl(&rep.indicators);
-    }
 
-    char start[length];
-    memset(start, 0, length);
+    char start[rep.length * 4];
+    memset(start, 0, sizeof(start));
     char* desc = start;
 
     if (xkb->names) {
@@ -3876,14 +3867,6 @@ XkbSendNames(ClientPtr client, XkbDescPtr xkb, xkbGetNamesReply rep)
             }
         }
     }
-
-    if ((desc - start) != (length)) {
-        ErrorF("[xkb] BOGUS LENGTH in write names, expected %d, got %ld\n",
-               length, (unsigned long) (desc - start));
-    }
-    WriteToClient(client, sizeof(rep), &rep);
-    WriteToClient(client, length, start);
-    return Success;
 }
 #undef _ADD_CARD32
 
@@ -3916,7 +3899,23 @@ ProcXkbGetNames(ClientPtr client)
         .nRadioGroups = xkb->names ? xkb->names->num_rg : 0
     };
     XkbComputeGetNamesReplySize(xkb, &rep);
-    return XkbSendNames(client, xkb, rep);
+
+    char payload_buf[rep.length * 4];
+    memset(payload_buf, 0, sizeof(payload_buf));
+
+    XkbAssembleNames(client, xkb, rep, payload_buf);
+
+    if (client->swapped) {
+        swaps(&rep.sequenceNumber);
+        swapl(&rep.length);
+        swapl(&rep.which);
+        swaps(&rep.virtualMods);
+        swapl(&rep.indicators);
+    }
+
+    WriteToClient(client, sizeof(rep), &rep);
+    WriteToClient(client, sizeof(payload_buf), payload_buf);
+    return Success;
 }
 
 /***====================================================================***/
@@ -6051,8 +6050,24 @@ ProcXkbGetKbdByName(ClientPtr client)
         WriteToClient(client, sizeof(buf), buf);
     }
 
-    if (reported & (XkbGBN_KeyNamesMask | XkbGBN_OtherNamesMask))
-        XkbSendNames(client, new, nrep);
+    if (reported & (XkbGBN_KeyNamesMask | XkbGBN_OtherNamesMask)) {
+        char buf[nrep.length * 4];
+        memset(buf, 0, sizeof(buf));
+
+        XkbAssembleNames(client, new, nrep, buf);
+
+        if (client->swapped) {
+            swaps(&nrep.sequenceNumber);
+            swapl(&nrep.length);
+            swapl(&nrep.which);
+            swaps(&nrep.virtualMods);
+            swapl(&nrep.indicators);
+        }
+
+        WriteToClient(client, sizeof(nrep), &nrep);
+        WriteToClient(client, sizeof(buf), buf);
+    }
+
     if (reported & XkbGBN_GeometryMask)
         XkbSendGeometry(client, new->geom, grep);