From 921706691a87c3ea5f5b92afd9b423e5f8c6e9d9 Mon Sep 17 00:00:00 2001 From: wm4 Date: Tue, 13 Jan 2015 14:47:47 +0100 Subject: [PATCH] qpeg: avoid pointless invalid memcpy() If refdata was NULL, the memcpy() ended up copying the same memory block onto itself, which is not only pointless, but also undefined behavior. Signed-off-by: Michael Niedermayer --- libavcodec/qpeg.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/libavcodec/qpeg.c b/libavcodec/qpeg.c index d61bceafd7..71f322b828 100644 --- a/libavcodec/qpeg.c +++ b/libavcodec/qpeg.c @@ -120,12 +120,13 @@ static void av_noinline qpeg_decode_inter(QpegContext *qctx, uint8_t *dst, int filled = 0; int orig_height; - if(!refdata) - refdata= dst; - - /* copy prev frame */ - for(i = 0; i < height; i++) - memcpy(dst + (i * stride), refdata + (i * stride), width); + if (refdata) { + /* copy prev frame */ + for (i = 0; i < height; i++) + memcpy(dst + (i * stride), refdata + (i * stride), width); + } else { + refdata = dst; + } orig_height = height; height--;