From 67b78a9f58db47cc28a239bd3a9d822e48ea3c0e Mon Sep 17 00:00:00 2001
From: "Enrico Weigelt, metux IT consult" <info@metux.net>
Date: Tue, 13 May 2025 14:40:34 +0200
Subject: [PATCH] randr: simplify reply assembly in
 ProcRRListProviderProperties()

Moving payload buffer assembly right into the same branch where the buffer is
allocated, so making the whole code flow easier to understand. Also moving the
byteswap there (when the fields should still be in CPU cache), instead of having
some callback doing it much later, so even more simplication.

As a nice by-product, that's also reducing some analyzer noise.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 randr/rrproviderproperty.c | 30 ++++++++++++++++++------------
 1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/randr/rrproviderproperty.c b/randr/rrproviderproperty.c
index 84bb724e0..1638ff4ca 100644
--- a/randr/rrproviderproperty.c
+++ b/randr/rrproviderproperty.c
@@ -335,7 +335,7 @@ int
 ProcRRListProviderProperties(ClientPtr client)
 {
     REQUEST(xRRListProviderPropertiesReq);
-    Atom *pAtoms = NULL, *temppAtoms;
+    Atom *pAtoms = NULL;
     int numProps = 0;
     RRProviderPtr provider;
     RRPropertyPtr prop;
@@ -346,9 +346,20 @@ ProcRRListProviderProperties(ClientPtr client)
 
     for (prop = provider->properties; prop; prop = prop->next)
         numProps++;
-    if (numProps)
-        if (!(pAtoms = xallocarray(numProps, sizeof(Atom))))
+
+    const Bool swapped = client->swapped;
+
+    if (numProps) {
+        if (!(pAtoms = calloc(numProps, sizeof(Atom))))
             return BadAlloc;
+        Atom *temppAtoms = pAtoms;
+        for (prop = provider->properties; prop; prop = prop->next) {
+            *temppAtoms = prop->propertyName;
+            if (swapped)
+                swapl(temppAtoms);
+            temppAtoms++;
+        }
+    }
 
     xRRListProviderPropertiesReply rep = {
         .type = X_Reply,
@@ -356,21 +367,16 @@ ProcRRListProviderProperties(ClientPtr client)
         .length = bytes_to_int32(numProps * sizeof(Atom)),
         .nAtoms = numProps
     };
-    if (client->swapped) {
+    if (swapped) {
         swaps(&rep.sequenceNumber);
         swapl(&rep.length);
         swaps(&rep.nAtoms);
     }
-    temppAtoms = pAtoms;
-    for (prop = provider->properties; prop; prop = prop->next)
-        *temppAtoms++ = prop->propertyName;
 
     WriteToClient(client, sizeof(xRRListProviderPropertiesReply), (char *) &rep);
-    if (numProps) {
-        client->pSwapReplyFunc = (ReplySwapPtr) Swap32Write;
-        WriteSwappedDataToClient(client, numProps * sizeof(Atom), pAtoms);
-        free(pAtoms);
-    }
+    WriteToClient(client, numProps * sizeof(Atom), pAtoms);
+
+    free(pAtoms);
     return Success;
 }