See the attached screenshot. There are meant to be two lines of text, each with a mix of normal and bold text. But the bold text is causing line breaks. The mixed text is implemented as a <description> with an embedded <label>, the <label> has a class that just sets font-weight. I tried adding display: inline to the label but that doesn't seem to make any difference. I suspect there's some simple CSS tweak here but I don't know what it is...

The problem happens only when the add-on name is too long to fit on a single line. To fix it, change the "label" to a "span", and add "display: inline" in its CSS.

I could swear I started out this way and was told not to mix html and xul. But I'll give it a shot.

(In reply to Andrew Swan [:aswan] from comment #3) > I could swear I started out this way and was told not to mix html and xul. Yes, I told you to not mix html and xul unless there was a reason to do it. This bug is the reason. Sorry :-(.

Comment on attachment 8832756 [details] Bug 1333168 Use <span> for addon name in permission dialog https://reviewboard.mozilla.org/r/108978/#review110290 ::: browser/modules/ExtensionsUI.jsm:177 (Diff revision 1) > if (name.length > 50) { > name = name.slice(0, 49) + "…"; > } > name = this._sanitizeName(name); > > - let addonLabel = `<label class="addon-webext-name">${name}</label>`; > + let addonLabel = `<span class="addon-webext-name">${name}</span>`; You need to make this change in showInstallNotification too, right? Now that it's no longer a label, should we rename this variable to eg. addonName?

Comment on attachment 8832756 [details] Bug 1333168 Use <span> for addon name in permission dialog https://reviewboard.mozilla.org/r/108978/#review110290 > You need to make this change in showInstallNotification too, right? > > Now that it's no longer a label, should we rename this variable to eg. addonName? Whoops, thanks, that's what I get for pushing late at night...

Comment on attachment 8832756 [details] Bug 1333168 Use <span> for addon name in permission dialog https://reviewboard.mozilla.org/r/108978/#review110378 Looks good (note: I haven't tested the patch locally, but I had tested with devtools the suggestion I proposed in comment 2, so I'm reasonably confident).

Pushed by aswan@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/c1fed3356757 Use <span> for addon name in permission dialog r=florian

Verified fixed on Firefox 54.0a1 (2017-02-20/21) under Windows 10 64-bit, Mac OS X 10.12.1 and Ubuntu 16.04 32-bit. Add-ons name are correctly displayed and there are no longer unnecessary line breaks.