1425660 - In Responsive Design Mode, `tabs.sendMessage` refuses to send

Status: RESOLVED DUPLICATE of bug 1394841

(WebExtensions :: Untriaged, defect)

Description

[Todd Wolfson]

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:57.0) Gecko/20100101 Firefox/57.0
Build ID: 20171130143849

Steps to reproduce:

- Clone https://gist.github.com/twolfson/c47ab162b73fd86a59e05ac91b455108
- Open Firefox and navigate to `about:debugging`
- Add our extension as a temporary add-on
- Open its "Debug" console
- Navigate to a normal website (e.g. <https://mozilla.org/>)
- Open our in-page Developer console
- Click our icon, look at "Debug" console, and verify message sending
- Look at our in-page Developer console and verify message logged
- Enter Responsive Design Mode
- Click our icon, look at "Debug" console, and verify message failing to send
- Look at our in-page Developer console and verify no message logged


Actual results:

No message was sent from background script (`global.js`) to content script (`injected.js`). Instead, we got error from `undefined`: "Error: Could not establish connection. Receiving end does not exist."


Expected results:

Message should be sent from background script (`global.js`) to content script (`injected.js`) and logged in in-page Developer Console