"Content-Length: 0"

[phmarek]

When trying to upload a file that you don't have access rights for, firefox happily goes ahead and sends a request with "Content-length: 0" and some mime boundary header but then no actual post data (as there's no content to send), resulting in (with #164) an EOF error.
(Without the patch, the server thread runs into a TCP timeout, as it waits for the never-sent mime boundary.)

POST /upload-file HTTP/1.1
Host: localhost:8080
User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:60.0) Gecko/20100101 Firefox/60.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: http://localhost:8080/
Content-Type: multipart/form-data; boundary=---------------------------179550789421416635281736454007
Content-Length: 0
DNT: 1
Connection: keep-alive
Upgrade-Insecure-Requests: 1

Resulting in this stack trace:

end of file on #<FLEXI-STREAMS:FLEXI-IO-STREAM {100BF9FC23}>
   [Condition of type END-OF-FILE]

Frames:
  0.  (READ-CHAR #<FLEXI-STREAMS:FLEXI-IO-STREAM {100BF9FC23}> T NIL #<unused argument>)
  1.  ((FLET RFC2388::RUN :IN RFC2388::READ-UNTIL-NEXT-BOUNDARY) #<BROADCAST-STREAM {10000321A3}>)
  2.  (RFC2388::READ-UNTIL-NEXT-BOUNDARY #<FLEXI-STREAMS:FLEXI-IO-STREAM {100BF9FC23}> "---------------------------129268202915739752981342792626" T NIL)
  3.  ((:METHOD RFC2388:PARSE-MIME (STREAM T)) #<FLEXI-STREAMS:FLEXI-IO-STREAM {100BF9FC23}> "---------------------------129268202915739752981342792626" :WRITE-CONTENT-TO-FILE T) [fast-method]
  4.  ((SB-PCL::EMF RFC2388:PARSE-MIME) #<unused argument> #<unused argument> #<FLEXI-STREAMS:FLEXI-IO-STREAM {100BF9FC23}> "---------------------------129268202915739752981342792626")
  5.  (HUNCHENTOOT::PARSE-RFC2388-FORM-DATA #<FLEXI-STREAMS:FLEXI-IO-STREAM {100BF9FC23}> "multipart/form-data; boundary=---------------------------129268202915739752981342792626" #<FLEXI-STREAMS::FLEXI-UTF..
  6.  ((FLET "FORM-FUN-4" :IN HUNCHENTOOT::PARSE-MULTIPART-FORM-DATA))
  7.  (HUNCHENTOOT::PARSE-MULTIPART-FORM-DATA #<HUNCHENTOOT:REQUEST {100BF9C0B3}> #<FLEXI-STREAMS::FLEXI-UTF-8-FORMAT (:UTF-8 :EOL-STYLE :LF) {10034A0AC3}>)
  8.  ((FLET "FORM-FUN-7" :IN HUNCHENTOOT::MAYBE-READ-POST-PARAMETERS))
  9.  (HUNCHENTOOT::MAYBE-READ-POST-PARAMETERS :REQUEST #<HUNCHENTOOT:REQUEST {100BF9C0B3}> :FORCE T :EXTERNAL-FORMAT NIL)
  10. ((:METHOD HUNCHENTOOT:POST-PARAMETERS :BEFORE (HUNCHENTOOT:REQUEST)) #<HUNCHENTOOT:REQUEST {100BF9C0B3}>) [fast-method]
  11. ((SB-PCL::EMF HUNCHENTOOT:POST-PARAMETERS) #<unused argument> #<unused argument> #<HUNCHENTOOT:REQUEST {100BF9C0B3}>)
  12. (HUNCHENTOOT:POST-PARAMETER "file" #<HUNCHENTOOT:REQUEST {100BF9C0B3}>)

I'm not sure about the correct way to handle that --

• should we just fail the complete request at some higher level (is "Content-length: 0" invalid?),
• should we fail only when arguments are being requested (as it seems to be now), or
• should we return NIL for this parameter only (as this parameter was never sent) and not fail?

[phmarek]

#170 solved that; only GET parameters are valid, POST data is returned as NIL (as it was not given correctly).