boundary not found in Content-Type: multipart/formdata

[nnamtug]

in function MultipartData.new(data, content_type), the boundary is searched by using the expression ";%s+boundary=(%S+)".

This works correctly for e.g. this Content-Type header:

Content-Type: multipart/form-data; boundary=AAAH...

But the whitespace after the semicolon is optional (and the pattern expects a whitespace). If the whitespace is not there, the field boundary is nil and parsing of the request will fail.

E.g. in when using Kong 0.8.3 with Oauth2 and a multipart upload, this fails as following:

share/lua/5.1/multipart.lua: in function 'decode'
share/lua/5.1/multipart.lua:112: in function 'Multipart'
share/lua/5.1/kong/plugins/oauth2/access.lua:93: in function 'retrieve_parameters'
share/lua/5.1/kong/plugins/oauth2/access.lua:359: in function 'parse_access_token'
share/lua/5.1/kong/plugins/oauth2/access.lua:412: in function 'execute'
share/lua/5.1/kong/plugins/oauth2/handler.lua:12: in function 'access'
share/lua/5.1/kong.lua:188: in function 'access'```

Solution: in multipart.lua:109 the value of boundary should also be found, if no whitespace is sent after the ; by the client in the value of the header Content-Type