Download continues after maxContentLength exceeded

#### Summary

The following code demonstrates the issue:

require('axios').get(
  'https://upload.wikimedia.org/wikipedia/commons/f/fe/A_Different_Slant_on_Carina.jpg',
  { maxContentLength: 2000 }
)
  .then(d => console.log('done'))
  .catch(e => console.log(e.toString()))

Expected behavior:

• The script exits immediately after printing “Error: maxContentLength size of 2000 exceeded”
• Not much more than 2KB was downloaded from the server

Actual behavior:

• The script prints “Error: maxContentLength size of 2000 exceeded”, then continues to download the remaining 52MB of data from the server. It takes about two minutes before it exits on my connection.

It’s possible to work around this by adding a cancellation token and manually canceling the request when an error is encountered. However, since the request never actually fires a “complete” event, it’s surprising that the download continues, only to have the data be thrown into the void.

#### Context

• axios version: v0.16.2
• Environment: node v8.4.0, macOS Sierra 10.12.6

[anulman]

Fix is released as part of 0.19.0; per @emilyemorehouse’s comment there should be a more targeted 0.18.1 release made available as well shortly.

Let’s all thank the maintainers and contributors for their generous work ❤️

[josh-keating]

What’s the likelihood of this PR getting approved / merged?

Sourceclear is raising this as a vulnerability, with this PR being the fix: https://www.sourceclear.com/vulnerability-database/security/denial-of-service-dos-/javascript/sid-6130