From f3176bae97796d84f8018da2f6f3bcb997aa07f2 Mon Sep 17 00:00:00 2001
From: "Enrico Weigelt, metux IT consult" <info@metux.net>
Date: Mon, 15 Jul 2024 21:59:02 +0200
Subject: [PATCH] xkb: XkbSendCompatMap(): little cleanup and simplification

Make it a bit simpler and easier to read.

calloc() and WriteToClient() can handle zero lengths very well.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 xkb/xkb.c | 81 +++++++++++++++++++++++++------------------------------
 1 file changed, 36 insertions(+), 45 deletions(-)

diff --git a/xkb/xkb.c b/xkb/xkb.c
index 01d8646d9..c845a990d 100644
--- a/xkb/xkb.c
+++ b/xkb/xkb.c
@@ -2806,52 +2806,45 @@ static int
 XkbSendCompatMap(ClientPtr client,
                  XkbCompatMapPtr compat, xkbGetCompatMapReply rep)
 {
-    char *data;
-    int size;
+    int sz = rep.length * sizeof(CARD32);
+    char *buf = calloc(1, sz);
+    if (sz && (!buf))
+        return BadAlloc;
 
-    if (rep.length > 0) {
-        data = calloc(rep.length, 4);
-        if (data) {
-            register unsigned i, bit;
-            xkbModsWireDesc *grp;
-            XkbSymInterpretPtr sym = &compat->sym_interpret[rep.firstSI];
-            xkbSymInterpretWireDesc *wire = (xkbSymInterpretWireDesc *) data;
+    if (sz) {
+        register unsigned i, bit;
+        xkbModsWireDesc *grp;
+        XkbSymInterpretPtr sym = &compat->sym_interpret[rep.firstSI];
+        xkbSymInterpretWireDesc *wire = (xkbSymInterpretWireDesc *) buf;
 
-            size = rep.length * 4;
-
-            for (i = 0; i < rep.nSI; i++, sym++, wire++) {
-                wire->sym = sym->sym;
-                wire->mods = sym->mods;
-                wire->match = sym->match;
-                wire->virtualMod = sym->virtual_mod;
-                wire->flags = sym->flags;
-                memcpy((char *) &wire->act, (char *) &sym->act,
-                       sz_xkbActionWireDesc);
-                if (client->swapped) {
-                    swapl(&wire->sym);
-                }
-            }
-            if (rep.groups) {
-                grp = (xkbModsWireDesc *) wire;
-                for (i = 0, bit = 1; i < XkbNumKbdGroups; i++, bit <<= 1) {
-                    if (rep.groups & bit) {
-                        grp->mask = compat->groups[i].mask;
-                        grp->realMods = compat->groups[i].real_mods;
-                        grp->virtualMods = compat->groups[i].vmods;
-                        if (client->swapped) {
-                            swaps(&grp->virtualMods);
-                        }
-                        grp++;
-                    }
-                }
-                wire = (xkbSymInterpretWireDesc *) grp;
+        for (i = 0; i < rep.nSI; i++, sym++, wire++) {
+            wire->sym = sym->sym;
+            wire->mods = sym->mods;
+            wire->match = sym->match;
+            wire->virtualMod = sym->virtual_mod;
+            wire->flags = sym->flags;
+            memcpy((char *) &wire->act, (char *) &sym->act,
+                   sz_xkbActionWireDesc);
+            if (client->swapped) {
+                swapl(&wire->sym);
             }
         }
-        else
-            return BadAlloc;
+        if (rep.groups) {
+            grp = (xkbModsWireDesc *) wire;
+            for (i = 0, bit = 1; i < XkbNumKbdGroups; i++, bit <<= 1) {
+                if (rep.groups & bit) {
+                    grp->mask = compat->groups[i].mask;
+                    grp->realMods = compat->groups[i].real_mods;
+                    grp->virtualMods = compat->groups[i].vmods;
+                    if (client->swapped) {
+                        swaps(&grp->virtualMods);
+                    }
+                    grp++;
+                }
+            }
+            wire = (xkbSymInterpretWireDesc *) grp;
+        }
     }
-    else
-        data = NULL;
 
     if (client->swapped) {
         swaps(&rep.sequenceNumber);
@@ -2862,10 +2855,8 @@ XkbSendCompatMap(ClientPtr client,
     }
 
     WriteToClient(client, sizeof(xkbGetCompatMapReply), &rep);
-    if (data) {
-        WriteToClient(client, size, data);
-        free((char *) data);
-    }
+    WriteToClient(client, sz, buf);
+    free(buf);
     return Success;
 }