Thank you for your continued patience. It is true that this bug is is about losing the font when clicking at the end of the line after clicking somewhere else. However, I'd like to consider other occasions where the font is lost, that is after inserting an image by paste.
Let's deal with this "off-topic" issue first: In Firefox, using <div contenteditable> you can paste in an image and then keep typing in the font that was used before the insertion. So as you concluded, TB must be doing something strange here. As for the clicking at the end of the line: In Firefox, again with a <div contenteditable> I created two texts with different fonts, clicking in one, typing in one font, then clicking in the other one, then clicking at the end of the first one again does NOT lose the font. So maybe this is not a Core/Editor bug, maybe it's solely a Thunderbird bug. To answer your question why I was looking in the editor for the click processing: pure ignorance. Of course you can click onto a static document where no editor is involved and the click will be processed. I will follow up on the other issues with the Thunderbird group https://groups.google.com/forum/#!topic/mozilla.dev.apps.thunderbird/1xtQ_nruGcw and keep you posted. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to thunderbird in Ubuntu. https://bugs.launchpad.net/bugs/584632 Title: composer changes font mid email Status in Mozilla Thunderbird Mail and News: Confirmed Status in thunderbird package in Ubuntu: Confirmed Bug description: Binary package hint: thunderbird As I'm typing my emails in Thunderbird, I can see what appears to be a font size change on screen, normally in the second line of text. The second line appear smaller than the first. It's barely perceptible, so half them time I think I am imagining it. Well, I've started Bccing to myself to check, and the emails I am receiving from myself are not only a different size, they're also a different font. Composer starts in some default serif, and by the second line is sans. I'd bee glad to email someone viz thunderbird, and also send along a screenshot of how it looks while I am typing. Thanks. To manage notifications about this bug go to: https://bugs.launchpad.net/thunderbird/+bug/584632/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp

