Negative progress value on file download

[richardgroves]

New Issue Checklist

• [x ] I am not disclosing a vulnerability.
• [ x] I am not just asking a question.
• [ x] I have searched through existing issues.
• [ x] I can reproduce the issue with the latest versions of Parse Server and the Parse ObjC SDK.

Issue Description

File download progress block can be called with a negative progress value

Steps to reproduce

Download a file from a server where the content length is not known/knowable

Actual Outcome

-22424 passed as progress of download when 243 bytes had been downloaded.

Expected Outcome

0 passed as progress if true value not knowable?

Environment

Parse Core 1.19.4, but same code problem exists in 2.02

Client

• Parse ObjC SDK version: 1.19.4 & all others up to 2.0.2

Server

• Parse Server version: NA
• Operating system: iOS 16.2
• Local or remote host (AWS, Azure, Google Cloud, Heroku, Digital Ocean, etc): Remote - Back4App

Database

• System (MongoDB or Postgres): Mongo
• Database version: 3.0
• Local or remote host (MongoDB Atlas, mLab, AWS, Azure, Google Cloud, etc): Remote - Back4App

Logs

NA

Narrative version:

It is possible to have a download progress block called with a negative progress value.

This occurs as the line:

Parse-SDK-iOS-OSX/Parse/Parse/Internal/Commands/CommandRunner/URLSession/Session/TaskDelegate/PFURLSessionFileDownloadTaskDelegate.m

Line 62 in b6ec05c

int progress = (int)(self.downloadedBytes / (double)self.response.expectedContentLength * 100);

does not include a check for self.response.expectedContentLength == NSURLResponseUnknownLength
(NSURLResponseUnknownLength = -1).

[parse-github-assistant]

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