1287347 - browser.downloads.download with blob:-URL: Access denied for URL blob:moz-extension

Status: RESOLVED DUPLICATE of bug 1271345

(WebExtensions :: Untriaged, defect)

Description

[Rob Wu [:robwu]]

Attachment: downloads-download-blob.zip

1. Load the attached extension.
2. The extension opens a tab with instructions, follow those instructions and you will basically try different ways of running

chrome.downloads.download({url:'blob:moz-extension://...'});

where the URL is actually created using URL.createObjectURL(blob),
and one <a download> test.

Expected:
At each of the four attempt, a download dialog should appear.

Actual (Firefox 47.0.1 and Firefox Nightly (50)):
- The chrome.downloads.download invocation fails with:
Error: Type error for parameter options (Error processing url: Error: Access denied for URL blob:moz-extension://9089d5f0-2813-4a73-b5aa-733b8d777294/6e0c929e-3e68-46ab-870c-894bec0df00b) for downloads.download.
- The dialog appears as expected when I use <a download> (unless e10s is enabled - see bug 1287346).

The failure originates from
http://searchfox.org/mozilla-central/rev/bfcc10319e4e3ce78367fa9bba9316f7eb5248b6/toolkit/components/extensions/Schemas.jsm#140

|this.principal| references |this.params.principal|, but the latter is not set.
http://searchfox.org/mozilla-central/rev/bfcc10319e4e3ce78367fa9bba9316f7eb5248b6/toolkit/components/extensions/Schemas.jsm#137

... because Schema.inject has callers that don't set the principal on |wrapperFunc|.
http://searchfox.org/mozilla-central/rev/bfcc10319e4e3ce78367fa9bba9316f7eb5248b6/toolkit/components/extensions/Schemas.jsm#1618

Comment 1

[Kris Maglione [:kmag]]

This should work since bug 1271345, and we definitely have tests for it.

Comment 2

[Rob Wu [:robwu]]

Just tested again on the latest build, it works. I guess that I only tested with 47 and an old Nightly 49, and not 50 itself. Sorry for the noise.