samvermette/SVHTTPRequest — comment on commit 27ba312fee932964f783449431effeebf0a22aa8
File:  line 0
By jvashishtha:

I actually returned -1 because of 2 reasons:
1) -1 is the value that is returned in NSURLResponse if the expected content length is unknown
2) To let the developer know in the progress block that the size is unknown by checking for -1. 0 can be the value at the start also, so there is no way the developer can know if he has to do anything in the UI. For eg, for -1 the developer can set the UIProgressView's progress to intermediate.