HTML email view: Some links don't open browser

[Simon-Laux]

More specifically, links without a schema, like academy.qt.io/enrollments

Expected: Open link in system browser Actual: Opening opens a blank page in the html viewer.

Tracking down the problem & Solution ideas

Foundation knowledge

The html email window has two parts: the ui and a sandboxed browser view with disable JS in which the html email is loaded.

Email source is loaded from the email:// scheme that is implemented in https://github.com/deltachat/deltachat-desktop/blob/ba6534b3a9d60ad3e602f770ba630849cc62b87c/src/main/windows/html_email.ts#L412-L420

The http/s handlers are overwritten by handlers that call the http request method of DC core, if allow_remote_content is activated.

Then there is link handling:

https://github.com/deltachat/deltachat-desktop/blob/ba6534b3a9d60ad3e602f770ba630849cc62b87c/src/main/windows/html_email.ts#L472-L493

This openLink function is called in two cases:

• sandboxedView.webContents.on( 'will-navigate', ... source
• sandboxedView.webContents.setWindowOpenHandler(details => { ... source

seems this is not enough to catch this case. I suspect it tries to open it via the email:// scheme, so we might need to check if it is a domain that is tried to be opened instead of index.html.

concerns:

• we might need to expand the function in the future to load embedded images/media from the email in some edge cases? maybe?
• it might be too late when we get the call to the link in the email scheme handler, the user might already get a white/blank screen and we can not reject the request?
• last resort could be to modify the html to fix those <a href= links, to add https-scheme, but not sure we want that, could lead to more edge cases/bugs.

If you want or need dev tools for the email content add this to the code in html_email.ts.

sandboxedView.webContents.openDevTools()

[farooqkz]

@Simon-Laux Thank you so much for the details :)

[farooqkz]

Okay after investigating, other than Simon's findings, I can also confirm that it's not http, https, file or email protocols either.

[farooqkz]

This does not trigger either when clicking on the link: https://www.electronjs.org/docs/latest/api/web-contents#event-will-frame-navigate