[FFmpeg-devel] [RFC PATCH v2] avutil/frame: fix remove_side_data

[Zhao Zhili]

remove_side_data is supposed to remove a single instance by design.
Since new_side_data() doesn't forbid add multiple instances of the
same type, remove_side_data should deal with that.
---
I'm afraid this patch makes it harder to enforce single entry per type.

 libavutil/frame.c | 2 +-
 libavutil/frame.h | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/libavutil/frame.c b/libavutil/frame.c
index dcf1fc3d17..e4038096c2 100644
--- a/libavutil/frame.c
+++ b/libavutil/frame.c
@@ -806,7 +806,7 @@ void av_frame_remove_side_data(AVFrame *frame, enum AVFrameSideDataType type)
 {
     int i;
 
-    for (i = 0; i < frame->nb_side_data; i++) {
+    for (i = frame->nb_side_data - 1; i >= 0; i--) {
         AVFrameSideData *sd = frame->side_data[i];
         if (sd->type == type) {
             free_side_data(&frame->side_data[i]);
diff --git a/libavutil/frame.h b/libavutil/frame.h
index 5d3231e7bb..b5afb58634 100644
--- a/libavutil/frame.h
+++ b/libavutil/frame.h
@@ -920,8 +920,7 @@ AVFrameSideData *av_frame_get_side_data(const AVFrame *frame,
                                         enum AVFrameSideDataType type);
 
 /**
- * If side data of the supplied type exists in the frame, free it and remove it
- * from the frame.
+ * Remove and free all side data instances of the given type.
  */
 void av_frame_remove_side_data(AVFrame *frame, enum AVFrameSideDataType type);
 
-- 
2.17.1