From 8094957e09a43e0dcbaebf36d01b48922119b2c4 Mon Sep 17 00:00:00 2001
From: Jonas Kvinge <jonas@jkvinge.net>
Date: Fri, 26 Apr 2019 20:40:42 +0200
Subject: [PATCH] Fix gst_buffer_unref assertion in chromaprinter

---
 src/musicbrainz/chromaprinter.cpp | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/musicbrainz/chromaprinter.cpp b/src/musicbrainz/chromaprinter.cpp
index c7ad99e2e..2f474c50e 100644
--- a/src/musicbrainz/chromaprinter.cpp
+++ b/src/musicbrainz/chromaprinter.cpp
@@ -204,12 +204,16 @@ GstFlowReturn Chromaprinter::NewBufferCallback(GstAppSink* app_sink,
   Chromaprinter* me = reinterpret_cast<Chromaprinter*>(self);
 
   GstSample* sample = gst_app_sink_pull_sample(app_sink);
+  if (!sample) return GST_FLOW_ERROR;
   GstBuffer* buffer = gst_sample_get_buffer(sample);
-  GstMapInfo map;
-  gst_buffer_map(buffer, &map, GST_MAP_READ);
-  me->buffer_.write(reinterpret_cast<const char*>(map.data), map.size);
-  gst_buffer_unmap(buffer, &map);
-  gst_buffer_unref(buffer);
+  if (buffer) {
+    GstMapInfo map;
+    if (gst_buffer_map(buffer, &map, GST_MAP_READ)) {
+      me->buffer_.write(reinterpret_cast<const char*>(map.data), map.size);
+      gst_buffer_unmap(buffer, &map);
+    }
+  }
+  gst_sample_unref(sample);
 
   return GST_FLOW_OK;
 }