Firefox and Thunderbird

I've used Thunderbird as my email client under Linux for quite a long time. I recall needing a gui email client because people (probably using Windows) were sending me stuff in styled text, mostly that could easily be sent as plain text. Anyway, it's been years.

But last Saturday morning, my main home machine rebooted. Twice. The logs showed nary a hint why. But afterwards, both Firefox and Thunderbird had an unacceptably small font, used for their menus and other dressings. The size of the content was easily changed. I'd never felt the need to change other font sizes. And there are three font sizes that matter. But only one had changed. I figured at first that i'd lost some font, and that these two applications needed it. But Google didn't seem to know where such files might be.

One of the suggestions was that the file userChrome.css could be modified. I ran "locate" to see where such a file might be. I didn't have one. A Ha! But, no, it's normal not to have one. And creating one didn't solve the problem.

There were other false leads.

What finally did it was to edit my /etc/X11/xorg.conf file, and in the "display" section for my nVidia card, i added the lines:
Option "UseEdidDpi" "FALSE"
Option "DPI" "100 x 100"

In particular, it sets my screen resolution to 100x100 dots per inch, rather than 75 dots per inch. And, i arrived at this result by measuring the screen, computing the resolution (in my head, despite having a computer in front of me that can perform a billion divides or so in a second).

No idea why a random reboot should cause this behavior. It'd been working for a decade at least. No idea why only those two applications should be affected. xorg.conf is supposed to affect everything. No idea why there seems to be a bunch of ways to address this issue. For example, userChrome.css made no difference at all. And, it was system wide, not user wide. I created a new user just to test this out.

I'm a Unix guru. But the complexity and rate of change has gotten so out of hand, that even i had huge problems getting this to work. We've totally lost focus. The documentation is out of date. There are multiple ways to do something, and only one works? This isn't Unix anymore.

But with this post, perhaps Goggle does know how to solve this problem now.