Content-Disposition: attachments; filename="5c2ca3d448cf7d16922acfdc.jpg"

Content-Disposition: attachment; filename="test.jpg"; filename*=utf-8''test.jpg

# https://docs.aiohttp.org/en/stable/multipart.html

# nix
import sys
import io

# async
import asyncio
import aiohttp

class debugWriter:
    
    def __init__(self):
        self.buffer=""
        
    async def write(self, stuff):
        self.buffer += stuff.decode("utf-8","ignore")
        
    def done(self):
        print(self.buffer[:200])
 

async def bug1():
    """This doesn't work because:
    
    - payload.py : Payload.set_content_disposition : gets called and it overwrites header with some default values
    
    """
    
    mpwriter = aiohttp.MultipartWriter('form-data')
    f=open("test.jpg","wb"); f.write("123".encode("utf-8")); f.close() # create a dummy file
    
    f=open("test.jpg","rb")
    subwriter = mpwriter.append(f, {
        aiohttp.hdrs.CONTENT_DISPOSITION : 'attachments; filename="5c2ca3d448cf7d16922acfdc.jpg"', # has no effect
        aiohttp.hdrs.CONTENT_TYPE : "image/whatever"
            })

    w = debugWriter()
    await mpwriter.write(w)
    w.done()
    f.close()
    

async def bug2():
    """This doesn't work because:
    
    - multipart.py : MultiparWriter.append : headers get constructed once and only when append is called.
    - .. calling set_content_disposition after that has no effect
    
    """
    mpwriter = aiohttp.MultipartWriter('form-data')
    f=open("test.jpg","wb"); f.write("123".encode("utf-8")); f.close() # create a dummy file
    
    f=open("test.jpg","rb")
    subwriter = mpwriter.append(f, {
        aiohttp.hdrs.CONTENT_TYPE : "image/whatever"
            })
    
    mpwriter.set_content_disposition('attachments', filename='5c2ca3d448cf7d16922acfdc.jpg') # has no effect
    
    w = debugWriter()
    await mpwriter.write(w)
    w.done()
    f.close()
    
    
if __name__ == '__main__':
    asyncio.get_event_loop().run_until_complete(bug1())
    asyncio.get_event_loop().run_until_complete(bug2())

def set_content_disposition(self,
                                disptype: str,
                                quote_fields: bool=True,
                                **params: Any) -> None:
        """Sets ``Content-Disposition`` header."""
        if self._headers is None:
            self._headers = CIMultiDict()

        if (hdrs.CONTENT_DISPOSITION in self._headers):
            print("set_content_disposition : CONTENT_DISPOSITION found : ", self._headers[hdrs.CONTENT_DISPOSITION])

        else:
            print("set_content_disposition : overwriting ")
            self._headers[hdrs.CONTENT_DISPOSITION] = content_disposition_header(
                disptype, quote_fields=quote_fields, **params)
        print("set_content_disposition : now ", self._headers[hdrs.CONTENT_DISPOSITION])