[pulseaudio-discuss] [PATCH] Don't crash if pa_stream_peek returns NULL

[Felipe Sateler]

From: Christer Stenbrenden <christer at uggwar.net>

pa_stream_peek can return NULL if either the buffer is empty or if it
has a hole. In either case we need to avoid derefencing the data
pointer. Additionally, if there is a hole, we need to call pa_stream_drop,
if the buffer is empty we should not call it.

Thanks to Christer Stenbrenden for the initial patch.
BugLink: https://bugs.debian.org/735898
---
 src/mainwindow.cc | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/mainwindow.cc b/src/mainwindow.cc
index 5d205fb..ff9ec52 100644
--- a/src/mainwindow.cc
+++ b/src/mainwindow.cc
@@ -493,6 +493,14 @@ static void read_callback(pa_stream *s, size_t length, void *userdata) {
         return;
     }
 
+    if (!data) {
+        // NULL data means either a hole or empty buffer.
+	// Only drop the stream when there is a hole (length > 0)
+        if (length)
+            pa_stream_drop(s);
+        return;
+    }
+
     assert(length > 0);
     assert(length % sizeof(float) == 0);
 
-- 
2.1.1