From 10c244cc89e80e1e924d442ccf40935bd7162178 Mon Sep 17 00:00:00 2001
From: Mina Nagy Zaki <mnzaki@gmail.com>
Date: Wed, 8 Jun 2011 19:24:25 +0300
Subject: [PATCH] lavfi: avfilter_merge_formats: handle case where inputs are
 same

This fixes a double-free crash if lists are the same due to the two
merge_ref() calls at the end of the (useless) merging that happens.

Signed-off-by: Anton Khirnov <anton@khirnov.net>
(cherry picked from commit 11b6a82412bcd372adf694a26d83b07d337e1325)

Conflicts:

	libavfilter/formats.c

Signed-off-by: Reinhard Tartler <siretart@tauware.de>
---
 libavfilter/formats.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavfilter/formats.c b/libavfilter/formats.c
index 1b58b50e9f..79baed03dc 100644
--- a/libavfilter/formats.c
+++ b/libavfilter/formats.c
@@ -44,6 +44,9 @@ AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b)
     AVFilterFormats *ret;
     unsigned i, j, k = 0;
 
+    if (a == b)
+        return a;
+
     if (a == b)
         return a;