[FFmpeg-cvslog] lavfi: avfilter_merge_formats: handle case where inputs are same

[Mina Nagy Zaki]

ffmpeg | branch: release/0.5 | Mina Nagy Zaki <mnzaki at gmail.com> | Wed Jun  8 19:24:25 2011 +0300| [0dfcbe5285f04964f5de5e15a4bfbf83fb9fd082] | committer: Anton Khirnov

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 at khirnov.net>
(cherry picked from commit 11b6a82412bcd372adf694a26d83b07d337e1325)

Conflicts:

	libavfilter/formats.c

Signed-off-by: Reinhard Tartler <siretart at tauware.de>
(cherry picked from commit e5f4e249422834f727bcd432b73af971277f1371)

Signed-off-by: Anton Khirnov <anton at khirnov.net>
(cherry picked from commit b6c5848a1f8fc2755ea70d325acaddae9fac45ab)

Signed-off-by: Anton Khirnov <anton at khirnov.net>
(cherry picked from commit a4e277312cacfb78ef7583ed0b4fe4ccf5a0bcb1)

Signed-off-by: Anton Khirnov <anton at khirnov.net>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=0dfcbe5285f04964f5de5e15a4bfbf83fb9fd082
---

 libavfilter/formats.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavfilter/formats.c b/libavfilter/formats.c
index 33fec16..c91f8b2 100644
--- a/libavfilter/formats.c
+++ b/libavfilter/formats.c
@@ -43,6 +43,9 @@ AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b)
     AVFilterFormats *ret;
     unsigned i, j, k = 0;
 
+    if (a == b)
+        return a;
+
     ret = av_mallocz(sizeof(AVFilterFormats));
 
     /* merge list of formats */