From 7b547e044cb8c42d83a06cc23f4a44970301c166 Mon Sep 17 00:00:00 2001
From: Elliot Chen <elliot.chen@nxp.com>
Date: Mon, 27 May 2024 15:41:23 +0900
Subject: [PATCH] autovideoconvert: should not forward the allocation query if
 no element is selected

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6927>
---
 .../gst/autoconvert/gstbaseautoconvert.c               | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/subprojects/gst-plugins-bad/gst/autoconvert/gstbaseautoconvert.c b/subprojects/gst-plugins-bad/gst/autoconvert/gstbaseautoconvert.c
index eecc493056..b928c115fb 100644
--- a/subprojects/gst-plugins-bad/gst/autoconvert/gstbaseautoconvert.c
+++ b/subprojects/gst-plugins-bad/gst/autoconvert/gstbaseautoconvert.c
@@ -1150,6 +1150,16 @@ gst_base_auto_convert_sink_query (GstPad * pad, GstObject * parent,
     return ret;
   }
 
+  /* Should not forward the allocation query downstream directly
+   * if no subelement is selected, otherwise it can influence
+   * the downstream allocation choices and upstream buffer usage.
+   */
+  if (GST_QUERY_TYPE (query) == GST_QUERY_ALLOCATION) {
+    GST_DEBUG_OBJECT (self,
+        "no subelement is selected yet, can't answer ALLOCATION query");
+    return FALSE;
+  }
+
 ignore_acceptcaps_failure:
 
   if (GST_QUERY_TYPE (query) == GST_QUERY_ACCEPT_CAPS) {