[FFmpeg-cvslog] lavfi/vf_drawbox.c: fix CID 1485004

[Ting Fu]

ffmpeg | branch: master | Ting Fu <ting.fu at intel.com> | Fri Jun  4 10:22:45 2021 +0800| [22d99589d8147913a2fad8ba23fca24f6d3f92c3] | committer: Guo Yejun

lavfi/vf_drawbox.c: fix CID 1485004

CID 1485004: Uninitialized variables (UNINIT)
Using uninitialized value "x" when calling "*pixel_belongs_to_region".

Signed-off-by: Ting Fu <ting.fu at intel.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=22d99589d8147913a2fad8ba23fca24f6d3f92c3
---

 libavfilter/vf_drawbox.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/libavfilter/vf_drawbox.c b/libavfilter/vf_drawbox.c
index fff78862e9..1e9e028650 100644
--- a/libavfilter/vf_drawbox.c
+++ b/libavfilter/vf_drawbox.c
@@ -126,8 +126,9 @@ static void draw_region(AVFrame *frame, DrawBoxContext *ctx, int left, int top,
         for (y = top; y < down; y++) {
             ASSIGN_THREE_CHANNELS
             if (ctx->invert_color) {
-                if (pixel_belongs_to_region(ctx, x, y))
-                    row[0][x] = 0xff - row[0][x];
+                for (x = left; x < right; x++)
+                    if (pixel_belongs_to_region(ctx, x, y))
+                        row[0][x] = 0xff - row[0][x];
             } else {
                 for (x = left; x < right; x++) {
                     double alpha = (double)ctx->yuv_color[A] / 255;