From 014954c3f7341358dd55eb20c4cb321cdd7a4ef1 Mon Sep 17 00:00:00 2001
From: "Enrico Weigelt, metux IT consult" <info@metux.net>
Date: Wed, 17 Jul 2024 18:15:58 +0200
Subject: [PATCH] (submit/cleanup-xv-dispatch) Xext: xv: ProcXvQueryAdaptors()
 use local stack buffer

Simplify sending by collecting in a local scoped buffer, so only one
WriteToClient() call is needed. This also makes further simplifications
by upcoming patches easier.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 Xext/xvdisp.c | 42 ++++++++++++++++++++++++++----------------
 1 file changed, 26 insertions(+), 16 deletions(-)

diff --git a/Xext/xvdisp.c b/Xext/xvdisp.c
index 7f06f5e12..4b34f17d5 100644
--- a/Xext/xvdisp.c
+++ b/Xext/xvdisp.c
@@ -179,9 +179,7 @@ ProcXvQueryAdaptors(ClientPtr client)
 static int
 ProcXvQueryEncodings(ClientPtr client)
 {
-    xvEncodingInfo einfo;
     int totalSize;
-    int nameSize;
     XvPortPtr pPort;
     int ne;
     XvEncodingPtr pe;
@@ -201,6 +199,11 @@ ProcXvQueryEncodings(ClientPtr client)
         pe++;
     }
 
+    char buf[totalSize];
+    memset(buf, 0, sizeof(buf));
+
+    char *walk = buf;
+
     xvQueryEncodingsReply rep = {
         .type = X_Reply,
         .sequenceNumber = client->sequence,
@@ -219,26 +222,33 @@ ProcXvQueryEncodings(ClientPtr client)
     ne = pPort->pAdaptor->nEncodings;
     pe = pPort->pAdaptor->pEncodings;
     while (ne--) {
-        einfo.encoding = pe->id;
-        einfo.name_size = nameSize = strlen(pe->name);
-        einfo.width = pe->width;
-        einfo.height = pe->height;
-        einfo.rate.numerator = pe->rate.numerator;
-        einfo.rate.denominator = pe->rate.denominator;
+        int nameSize;
+        xvEncodingInfo *einfo = (xvEncodingInfo*)walk;
+
+        einfo->encoding = pe->id;
+        einfo->name_size = nameSize = strlen(pe->name);
+        einfo->width = pe->width;
+        einfo->height = pe->height;
+        einfo->rate.numerator = pe->rate.numerator;
+        einfo->rate.denominator = pe->rate.denominator;
 
         if (client->swapped) {
-            swapl(&einfo.encoding);
-            swaps(&einfo.name_size);
-            swaps(&einfo.width);
-            swaps(&einfo.height);
-            swapl(&einfo.rate.numerator);
-            swapl(&einfo.rate.denominator);
+            swapl(&einfo->encoding);
+            swaps(&einfo->name_size);
+            swaps(&einfo->width);
+            swaps(&einfo->height);
+            swapl(&einfo->rate.numerator);
+            swapl(&einfo->rate.denominator);
         }
-        WriteToClient(client, sizeof(einfo), &einfo);
-        WriteToClient(client, nameSize, pe->name);
+
+        walk += sizeof(xvEncodingInfo);
+        memcpy(walk, pe->name, nameSize);
+        walk += pad_to_int32(nameSize);
+
         pe++;
     }
 
+    WriteToClient(client, sizeof(buf), buf);
     return Success;
 }