This is a demo from https://github.com/mbarnig/WKWebView. But add upload file function.
In page, clicked the 'choose file' button, then upload a file which name contains Chinese(or non-English characters)， you may found upload failed. Seems like any page use "<input type='file'>" to upload file would not work right too.
This may a WKWebView bug?
Waiting for solution...
Here is a string of Chinese:
"这是中文"
you can use this line of Chinese to rename your file and do some tests.
StackOverFlow Quesion: https://stackoverflow.com/questions/44303980/wkwebview-upload-file-which-name-contains-chinese-character-results-in-garbled-c