This is quite urgent because it affects badly any content blocker webextension (most obviously NoScript / uBlock), which are unable to "see", let alone block, any 3rd party request from locally opened files, including scripts.
According to user reports, this is a 74 regression.
Steps to reproduce:
- unzip the attached WebRequestFromFile.zip in a local directory and install the manifest.json it contains as a temporary addon and click the "Inspect"
- Move the test.html file from the aforementioned directory to somewhere else outside (not a subdirectory, see "Fun fact" below), and open it in Firefox
- Check the console in the Toolbox - Extension tab
No event is logged in the console.
The console should show two log lines, one for onBeforeRequest and the other for onHeadersReceived.
Fun fact that left me scraping my head for a while:
If I opened test.html from
or from a subdirectory, the bug was NOT reproducible (both events get logged).
Wherever else I placed the file (either by moving, copying or symlinking it), other than there or in a subdirectory within, the bug was reliably reproducible. I've attempted any kind of variation (path length, path components, even just renaming the same directory with just one character change), but the mystery persisted.
Then the enlightenment: I tried to move the temporary add-on path, rather than the file, and could confirm that the bug is not reproducible if the HTML file is in the same path as the extension or in a subpath :D (bonus points to whomever can explain why).