From 182404fde6bcacf5e2f05424fde4073c96c2474e Mon Sep 17 00:00:00 2001
From: "Enrico Weigelt, metux IT consult" <info@metux.net>
Date: Thu, 25 Jul 2024 16:01:58 +0200
Subject: [PATCH] xkb: split XkbSendMap()

This function is a funny beast: it assembles and writes out an xkbGetMapReply,
called in two different cases, ProcXkbGetMap() 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: XkbAssembleMap() 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 | 71 +++++++++++++++++++++++++++++++++----------------------
 1 file changed, 43 insertions(+), 28 deletions(-)

diff --git a/xkb/xkb.c b/xkb/xkb.c
index 6a387fac5..df1dfbb0b 100644
--- a/xkb/xkb.c
+++ b/xkb/xkb.c
@@ -1403,16 +1403,9 @@ XkbComputeGetMapReplySize(XkbDescPtr xkb, xkbGetMapReply * rep)
     return Success;
 }
 
-static int
-XkbSendMap(ClientPtr client, XkbDescPtr xkb, xkbGetMapReply rep)
+static void
+XkbAssembleMap(ClientPtr client, XkbDescPtr xkb, xkbGetMapReply rep, char *desc)
 {
-    int len = (rep.length * sizeof(CARD32)) - (sizeof(xkbGetMapReply) - sizeof(xGenericReply));
-    char *start = calloc(1, len);
-    if (!start)
-        return BadAlloc;
-
-    char *desc = start;
-
     if (rep.nTypes > 0)
         desc = XkbWriteKeyTypes(xkb, rep.firstType, rep.nTypes, desc, client);
     if (rep.nKeySyms > 0)
@@ -1437,22 +1430,6 @@ XkbSendMap(ClientPtr client, XkbDescPtr xkb, xkbGetMapReply rep)
         desc = XkbWriteModifierMap(xkb, rep.firstModMapKey, rep.nModMapKeys, desc);
     if (rep.totalVModMapKeys > 0)
         desc = XkbWriteVirtualModMap(xkb, rep.firstVModMapKey, rep.nVModMapKeys, desc);
-    if ((desc - start) != (len)) {
-        ErrorF
-            ("[xkb] BOGUS LENGTH in write keyboard desc, expected %d, got %ld\n",
-             len, (unsigned long) (desc - start));
-    }
-    if (client->swapped) {
-        swaps(&rep.sequenceNumber);
-        swapl(&rep.length);
-        swaps(&rep.present);
-        swaps(&rep.totalSyms);
-        swaps(&rep.totalActs);
-    }
-    WriteToClient(client, sizeof(xkbGetMapReply), &rep);
-    WriteToClient(client, len, start);
-    free(start);
-    return Success;
 }
 
 int
@@ -1567,7 +1544,26 @@ ProcXkbGetMap(ClientPtr client)
 
     if ((status = XkbComputeGetMapReplySize(xkb, &rep)) != Success)
         return status;
-    return XkbSendMap(client, xkb, rep);
+
+    int payload_len = (rep.length * sizeof(CARD32)) - (sizeof(xkbGetMapReply) - sizeof(xGenericReply));
+    char *payload_buf = calloc(1, payload_len);
+    if (!payload_buf)
+        return BadAlloc;
+
+    XkbAssembleMap(client, xkb, rep, payload_buf);
+
+    if (client->swapped) {
+        swaps(&rep.sequenceNumber);
+        swapl(&rep.length);
+        swaps(&rep.present);
+        swaps(&rep.totalSyms);
+        swaps(&rep.totalActs);
+    }
+
+    WriteToClient(client, sizeof(xkbGetMapReply), &rep);
+    WriteToClient(client, payload_len, payload_buf);
+    free(payload_buf);
+    return Success;
 }
 
 /***====================================================================***/
@@ -6048,8 +6044,27 @@ ProcXkbGetKbdByName(ClientPtr client)
         swaps(&rep.reported);
     }
     WriteToClient(client, SIZEOF(xkbGetKbdByNameReply), &rep);
-    if (reported & (XkbGBN_SymbolsMask | XkbGBN_TypesMask))
-        XkbSendMap(client, new, mrep);
+
+    if (reported & (XkbGBN_SymbolsMask | XkbGBN_TypesMask)) {
+        int sz = ((mrep.length * sizeof(CARD32)) - (sizeof(mrep) - sizeof(xGenericReply)));
+        char *buf = calloc(1, sz);
+        if (!buf)
+            return BadAlloc;
+
+        XkbAssembleMap(client, xkb, mrep, buf);
+
+        if (client->swapped) {
+            swaps(&mrep.sequenceNumber);
+            swapl(&mrep.length);
+            swaps(&mrep.present);
+            swaps(&mrep.totalSyms);
+            swaps(&mrep.totalActs);
+        }
+        WriteToClient(client, sizeof(mrep), &mrep);
+        WriteToClient(client, sizeof(buf), buf);
+        free(buf);
+    }
+
     if (reported & XkbGBN_CompatMapMask)
         XkbSendCompatMap(client, new->compat, crep);
     if (reported & XkbGBN_IndicatorMapMask)