Prerequisites

• [ 🗸 ] I verified that this is not a filter issue
  • Filter issues MUST be reported at filter issue tracker
• [ 🗸 ] This is not a support issue or a question
  • Support issues and questions are handled at /r/uBlockOrigin
• [ 🗸 ] I performed a cursory search of the issue tracker to avoid opening a duplicate issue
  • Your issue may already be reported.
• I tried to reproduce the issue when...
  • [ 🗸 ] uBlock Origin is the only extension
  • [ 🗸 ] uBlock Origin with default lists/settings
  • [ 🗸 ] using a new, unmodified browser profile
• [ 🗸 ] I am running the latest version of uBlock Origin
• [ 🗸 ] I checked the documentation to understand that the issue I report is not a normal behavior

Description

When uBlock blocks remote fonts, the downloaded pages (except images) in the disk cache are not stored correctly: they are not then loaded offline, but should be loaded.

A specific URL where the issue occurs

https://example.com/

Steps to Reproduce

1. Create a new clean Firefox profile.
2. Install uBlock Origin (https://addons.mozilla.org/firefox/addon/ublock-origin/).
3. In uBlock Origin, enable "no remote fonts".
4. Go online mode and download a page (not an image), for example, https://example.com/ (checked). (I'm using localhost.)
5. Go offline mode and hold the browser in it.
6. The option "no remote fonts" can be turned off or not to change – it does not matter.
7. Reload the page opened on step 4 from the disk cache. 2 options: a and b:
   7.a. Re-open the tab with this page.
   7.b.1. "Reload the page bypassing the cache" (Ctrl+F5). (The result is not important: in fact, in offline mode, this will reload the page from the disk cache without checking it.)
   7.b.2. "Reload this Page with cache" (F5).
   The page will not load from the cache, but will report a "browser is offline mode" error. But the page should load.
   Disregarding the "no remote fonts" is changing the case, but I think that the blocking is needed. Cache is also needed.

Expected behavior:

The page will load from the cache.

Actual behavior:

The page will not load from the cache.

Your environment

• uBlock Origin version: 1.16.20.
• Browser Name and version: Firefox 56.
• Operating System and version: Linux Ubuntu 18.