Reproduction of the Chrome 48 Cache problem (Chromium issue 570622)

Setting up

• clone
• npm install
• node index.js

This will serve up a local server using etags for cache control

reproduction of the problem

• install chrome 48.0.2564.41 beta-m (64-bit)
• goto http://localhost:6005
• press the buttons

observed problems

• Using sync xmlhttp loading, the response is empty on the second click
  • the /test resource is cached correctly, as verified by going to chrome://cache
  • in chrome network inspector, it is verified that the response is indeed empty
• the problem does not occur when cache is disabled
• the problem does not occur when etags are disabled
• the problem does not occur using async xmlhttp or fetch

Public example

The login page at https://businessportal.apsmos.com/ uses the dojo js framework. This framework uses synchronous xmlhttprequests to resolve its dependencies. The problem reproduces after a few refreshes.

Note that in response to the empty response, dojo's fallback resource loading mechanism is triggered, which results in a bunch of 404's. The underlying problem however, is the empty cache response.

Also note that the "disable cache while devtools is open" feature of chrome dev tools should be disabled.

Chromium issue reference

https://code.google.com/p/chromium/issues/detail?id=570622