From 9b3959214d4dc79e8ac694865a3eb8189840fa71 Mon Sep 17 00:00:00 2001
From: "Enrico Weigelt, metux IT consult" <info@metux.net>
Date: Thu, 25 Jul 2024 17:47:47 +0200
Subject: [PATCH] xkb: split XkbSendGeometry()

This function is a funny beast: it assembles and writes out an xkbGetGeometryReply,
called in two different cases, ProcXkbGetGeometry() 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: XkbAssembleGeometry() 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 | 91 +++++++++++++++++++++++++++++++++----------------------
 1 file changed, 54 insertions(+), 37 deletions(-)

diff --git a/xkb/xkb.c b/xkb/xkb.c
index b77622163..efc273291 100644
--- a/xkb/xkb.c
+++ b/xkb/xkb.c
@@ -4914,18 +4914,14 @@ XkbComputeGetGeometryReplySize(XkbGeometryPtr geom,
     }
     return Success;
 }
-static int
-XkbSendGeometry(ClientPtr client,
-                XkbGeometryPtr geom, xkbGetGeometryReply rep)
-{
-    char *desc, *start = NULL;
-    int len = 0;
 
+static void
+XkbAssembleGeometry(ClientPtr client,
+                    XkbGeometryPtr geom,
+                    xkbGetGeometryReply rep,
+                    char *desc)
+{
     if (geom != NULL) {
-        start = desc = calloc(rep.length, sizeof(CARD32));
-        if (!start)
-            return BadAlloc;
-        len = rep.length * sizeof(CARD32);
         desc = XkbWriteCountedString(desc, geom->label_font, client->swapped);
         if (rep.nProperties > 0)
             desc = XkbWriteGeomProperties(desc, geom, client->swapped);
@@ -4940,31 +4936,7 @@ XkbSendGeometry(ClientPtr client,
                                        client->swapped);
         if (rep.nKeyAliases > 0)
             desc = XkbWriteGeomKeyAliases(desc, geom, client->swapped);
-        if ((desc - start) != (len)) {
-            ErrorF
-                ("[xkb] BOGUS LENGTH in XkbSendGeometry, expected %d, got %ld\n",
-                 len, (unsigned long) (desc - start));
-        }
     }
-    if (client->swapped) {
-        swaps(&rep.sequenceNumber);
-        swapl(&rep.length);
-        swapl(&rep.name);
-        swaps(&rep.widthMM);
-        swaps(&rep.heightMM);
-        swaps(&rep.nProperties);
-        swaps(&rep.nColors);
-        swaps(&rep.nShapes);
-        swaps(&rep.nSections);
-        swaps(&rep.nDoodads);
-        swaps(&rep.nKeyAliases);
-    }
-    WriteToClient(client, sizeof(xkbGetGeometryReply), &rep);
-    if (len > 0)
-        WriteToClient(client, len, start);
-    if (start != NULL)
-        free((char *) start);
-    return Success;
 }
 
 int
@@ -4995,7 +4967,32 @@ ProcXkbGetGeometry(ClientPtr client)
     if (status != Success)
         goto free_out;
 
-    status = XkbSendGeometry(client, geom, rep);
+    int len = rep.length * sizeof(CARD32);
+    char *buf = calloc(1, len);
+    if (!buf) {
+        status = BadAlloc;
+        goto free_out;
+    }
+
+    XkbAssembleGeometry(client, geom, rep, buf);
+
+    if (client->swapped) {
+        swaps(&rep.sequenceNumber);
+        swapl(&rep.length);
+        swapl(&rep.name);
+        swaps(&rep.widthMM);
+        swaps(&rep.heightMM);
+        swaps(&rep.nProperties);
+        swaps(&rep.nColors);
+        swaps(&rep.nShapes);
+        swaps(&rep.nSections);
+        swaps(&rep.nDoodads);
+        swaps(&rep.nKeyAliases);
+    }
+
+    WriteToClient(client, sizeof(xkbGetGeometryReply), &rep);
+    WriteToClient(client, len, buf);
+    free(buf);
 
 free_out:
     if (shouldFree)
@@ -6130,8 +6127,28 @@ ProcXkbGetKbdByName(ClientPtr client)
         free(buf);
     }
 
-    if (reported & XkbGBN_GeometryMask)
-        XkbSendGeometry(client, new->geom, grep);
+    if (reported & XkbGBN_GeometryMask) {
+        char buf[grep.length * 4];
+
+        XkbAssembleGeometry(client, new->geom, grep, buf);
+
+        if (client->swapped) {
+            swaps(&grep.sequenceNumber);
+            swapl(&grep.length);
+            swapl(&grep.name);
+            swaps(&grep.widthMM);
+            swaps(&grep.heightMM);
+            swaps(&grep.nProperties);
+            swaps(&grep.nColors);
+            swaps(&grep.nShapes);
+            swaps(&grep.nSections);
+            swaps(&grep.nDoodads);
+            swaps(&grep.nKeyAliases);
+        }
+
+        WriteToClient(client, sizeof(xkbGetGeometryReply), &grep);
+        WriteToClient(client, sizeof(buf), buf);
+    }
 
     if (loaded) {
         XkbDescPtr old_xkb;