User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:67.0) Gecko/20100101 Firefox/67.0

Steps to reproduce:

Install lastpass. Open debugger, open source with script.

Actual results:

Line numbers greyed out, unable to set breakpoint in script.

Expected results:

Breakpoint should be set, script lines should be white in dark mode / black in normal theme.

Honza, could you try and reproduce?

Check the screenshots in https://perfht.ml/2W753QY . Works for me, assuming the file to debug is the content script moz-extension://5c97f42c-16e3-de46-901a-4f9f0e2a7a03/onloadwff.js

It takes a while for lines to be "switched on", the source is rendered fast but code mirror is churning on something before the active lines appear. Related to https://github.com/devtools-html/debugger.html/issues/7134

Andy, have you waited a moment for lines to appear or reload with debugger open?

Working fine, last pass not installed, test html page.

Installed lastpass (not loggged in), refreshed page, line breaks not available.

I am sure it is not a question of waiting, I assume if it was a question of a delay, lastpass extension would not affect it - it just won't allow any toggle except on the first line which isn't a script line.

Thanks for looking into it.

Logan, since you worked on the related bug 1535246, any idea how extensions can effect breakpoints for HTML files? If this is something that content scripts cause, a lot of users could be affected.

The core issue here is that https://bugzilla.mozilla.org/show_bug.cgi?id=1535246 has not been uplifted.

This is causing an issue for LastPass in this case because it injects its own inline script into the page somehow, though I haven't dug into the details, and that script one single long line and is apparently on line 1. Because https://bugzilla.mozilla.org/show_bug.cgi?id=1535246 has not been uplifted, we query for column breakpoint positions in the HTML file, and get the first one, and in this case the first one happens to be the one added by Lastpass, causing us to only highlight the first line as a breakable line, rather than the first <script> in the user's own HTML.

Uplifting is likely the only option we have. The script isn't visible in the HTML, which may be surprising, but the way we load HTML is already a bit roundabout, so it is possible that LastPass is just able to hook into the code before parsing at page load, but then not able or taking into account the need to do it for when the debugger queries for the HTML source.

I'll leave this issue for us to discuss uplifting, but I've also filed https://bugzilla.mozilla.org/show_bug.cgi?id=1548707 since either way the extension's behavior shouldn't be causing this one way or the other.

The priority flag is not set for this bug.
:jlast, could you have a look please?

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We have decided to not uplift the fix. Logan is this okay to close?

Yep!