RandomFlip return wrong keypoint flip result

[zero0kiriyu]

The current _flip_keypoint function in RandomFlip return the concatenate of keypoints and meta_info

mmcv/mmcv/transforms/processing.py

Line 1262 in 4ae327f

flipped = np.concatenate([keypoints, meta_info], axis=-1)

while the keypoints is the original input and is not fliped.

The correct code should be

flipped = np.concatenate([flipped, meta_info], axis=-1)

[zhouzaida]

Hi @zero0kiriyu , thanks for your report. Are you interested in making a PR to fix this issue?