From 2cfdc16faed93a8d5d1ec391788547409df986de Mon Sep 17 00:00:00 2001
From: Ondrej Holy <oholy@redhat.com>
Date: Thu, 26 Mar 2026 15:57:28 +0100
Subject: [PATCH] [channels,video] unify error handling

Partial backport of commit 635ae3c8193256db01774fab5ff11bcae57aed6b.

Made-with: Cursor
---
 channels/video/client/video_main.c | 45 ++++++++++++++++++++++--------
 1 file changed, 34 insertions(+), 11 deletions(-)

diff --git a/channels/video/client/video_main.c b/channels/video/client/video_main.c
index a8031fc86..641231b1d 100644
--- a/channels/video/client/video_main.c
+++ b/channels/video/client/video_main.c
@@ -25,7 +25,9 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include <winpr/assert.h>
 #include <winpr/crt.h>
+#include <winpr/error.h>
 #include <winpr/synch.h>
 #include <winpr/print.h>
 #include <winpr/stream.h>
@@ -351,14 +353,24 @@ static void VideoClientContextPriv_free(VideoClientContextPriv* priv)
 	free(priv);
 }
 
+static UINT video_channel_write(VIDEO_PLUGIN* video, const BYTE* data, UINT32 length)
+{
+	WINPR_ASSERT(video);
+
+	if (!video->control_callback || !video->control_callback->channel_callback)
+		return ERROR_BAD_CONFIGURATION;
+	IWTSVirtualChannel* channel = video->control_callback->channel_callback->channel;
+	if (!channel || !channel->Write)
+		return ERROR_BAD_CONFIGURATION;
+	return channel->Write(channel, length, data, NULL);
+}
+
 static UINT video_control_send_presentation_response(VideoClientContext* context,
                                                      TSMM_PRESENTATION_RESPONSE* resp)
 {
 	BYTE buf[12];
 	wStream* s;
 	VIDEO_PLUGIN* video = (VIDEO_PLUGIN*)context->handle;
-	IWTSVirtualChannel* channel;
-	UINT ret;
 
 	s = Stream_New(buf, 12);
 	if (!s)
@@ -370,11 +382,9 @@ static UINT video_control_send_presentation_response(VideoClientContext* context
 	Stream_Zero(s, 3);
 	Stream_SealLength(s);
 
-	channel = video->control_callback->channel_callback->channel;
-	ret = channel->Write(channel, 12, buf, NULL);
 	Stream_Free(s, FALSE);
 
-	return ret;
+	return video_channel_write(video, buf, sizeof(buf));
 }
 
 static BOOL video_onMappedGeometryUpdate(MAPPED_GEOMETRY* geometry)
@@ -592,8 +602,6 @@ static UINT video_control_send_client_notification(VideoClientContext* context,
 	BYTE buf[100];
 	wStream* s;
 	VIDEO_PLUGIN* video = (VIDEO_PLUGIN*)context->handle;
-	IWTSVirtualChannel* channel;
-	UINT ret;
 	UINT32 cbSize;
 
 	s = Stream_New(buf, 30);
@@ -627,10 +635,7 @@ static UINT video_control_send_client_notification(VideoClientContext* context,
 	Stream_Write_UINT32(s, cbSize);
 	Stream_Free(s, FALSE);
 
-	channel = video->control_callback->channel_callback->channel;
-	ret = channel->Write(channel, cbSize, buf, NULL);
-
-	return ret;
+	return video_channel_write(video, buf, cbSize);
 }
 
 static void video_timer(VideoClientContext* video, UINT64 now)
@@ -952,12 +957,30 @@ static UINT video_data_on_data_received(IWTSVirtualChannelCallback* pChannelCall
  */
 static UINT video_control_on_close(IWTSVirtualChannelCallback* pChannelCallback)
 {
+	if (pChannelCallback)
+	{
+		VIDEO_LISTENER_CALLBACK* listener_callback = (VIDEO_LISTENER_CALLBACK*)pChannelCallback;
+		VIDEO_PLUGIN* video = (VIDEO_PLUGIN*)listener_callback->plugin;
+		if (video && video->control_callback)
+		{
+			video->control_callback->channel_callback = NULL;
+		}
+	}
 	free(pChannelCallback);
 	return CHANNEL_RC_OK;
 }
 
 static UINT video_data_on_close(IWTSVirtualChannelCallback* pChannelCallback)
 {
+	if (pChannelCallback)
+	{
+		VIDEO_LISTENER_CALLBACK* listener_callback = (VIDEO_LISTENER_CALLBACK*)pChannelCallback;
+		VIDEO_PLUGIN* video = (VIDEO_PLUGIN*)listener_callback->plugin;
+		if (video && video->data_callback)
+		{
+			video->data_callback->channel_callback = NULL;
+		}
+	}
 	free(pChannelCallback);
 	return CHANNEL_RC_OK;
 }
-- 
2.53.0