SOLVED: Latest Firefox ESR is broken with respect to zoom

[pccobbler]

I have multiple systems: Linux Mint LMDE Cinnamon, Devuan Cinnamon, and Sparky Linux MATE. All employ Firefox ESR and are based on Debian. With the latest update, Firefox has zoomed-in; pages that used to be readable now require a zoom-out to 80%. I tried setting layout.css.devPixelsPerPx in about:config to 0.0. but that does not fix the problem. Does everyone else use the data-mining Chrome?

In case it matters, the hardware is an HP laptop with Intel 3rd Generation Core processor, 8 GB memory, and SSD connected via USB 3.0. And Cinnamon LargeFont is set to true.

[arochester]

Linux Mint LMDE Cinnamon, Devuan Cinnamon, and Sparky Linux MATE.

They might be DERIVED FROM Debian, but they are not Debian.

Does everyone else use the data-mining Chrome?

What's wrong with Chromium?

[pccobbler]

@arochester

Yes, I am aware that the three distros are Debian spins. In a few days, I will build a Debian system to test your theory.

As for Chromium, I thought it did not self-update and retained some data-mining features (see below URL). I install Vivaldi for that reason.
https://github.com/Eloston/ungoogled-chromium

[arochester]

Firefox ESR is OK here. Default is 100%. Which release do you have? Currently 78.4.0esr

What does your Zoom Preference say? Firefox>Preferences>Zoom

[sgosnell]

The default zoom level for Firefox is configurable in the settings. It appears that it isn't broken, just misconfigured.

Mint is based on Ubuntu, not Debian. Although Ubuntu is based on Debian Unstable, by the time you get to Mint it's rather different. Mint and Ubuntu have their own forums, which would probably be a better place to try.

[sunrat]

Mint is based on Ubuntu, not Debian.

LMDE is based on Debian - "Linux Mint Debian Edition". Doesn't make it Debian though and any issues may not relate to anything in Debian.

[sgosnell]

I missed the LMDE, but still it's not the same. LMDE is based on Debian Testing, but is very different. I used it for awhile some years back, but being based on Testing makes it somewhat problematic. Testing is the last Debian version that I would consider. But I think that's all irrelevant. I believe the issue is probably in Firefox settings, which are easily changed.

[pccobbler]

78.4.0esr is the version on LMDE, which is where I am right now. Zoom is at 100%.

I'm using LMDE, not the Ubuntu version, which I think is a mistake. I don't think Linux Mint Ubuntu has this problem. I think I'll wipe the drive and install Linux Mint Ubuntu.

Setting zoom is not a solution, as every page remembers its own setting. Been there, done that. Life is too short to be forced to zoom-out on every new page.

As for Debian != spins, of course, but it's rather curious that three spins have the exact same problem.

[LE_746F6D617A7A69]

Life is too short to be forced to zoom-out on every new page.

It takes less than 1s to press CTRL and turn the Mouse Wheel to adjust the zoom ratio ...
Definitely it's much faster than distro-hopping - this is truly a big waste of time

Firefox -> Preferences -> Default_Zoom <option: Zoom text only> does the job in case if You have a problem with the default DPI setting for your computer screen.

[Deb-fan]

Think it's a config issue, though personally have pretty much always used whatever happens to be latest Firefox gotten directly from Mozilla. Never really used the ESR thing, at least not more than really briefly. You're getting and installing this from where ? Not sharing a profile or whatever between these instances of FF on these different installs ? All use any kind of extension which could be related to the issue ? Has to be something in common to be suffering this on 3 different OS's. Imported anything into all 3 of them, if so what ? Overall sounds like a really oddball problem, would like to know what's going on with it.

Just-4-record: Internet says Ubuntu LTS is based on a Debian testing snapshot(didn't know that.) Didn't even know Ubuntu releases rely heavily on unstable either. Also LMDE switched over to stable 2 releases ago, LMDE3 was Stretch and 4 is Buster. Agree with sgosnell's thoughts on the testing branch, assuming Linux Mint got tired of experiencing problems with using it, so did the wise + considerate thing for the users and switched over to tracking stable releases. First couple 1-2 were based on testing, presumably for the somewhat newer software pkgs, though remember were noted to tend towards being unstable and buggy too. Would think latest Firefox would be available in the LM repo's for LMDE4 ?

Started with LM10, still have a soft spot for the distro, always has amused me to see them piggy backing on Ubuntu, the way Ubuntu piggy backs on Debian proper.

[sgosnell]

You can set the default zoom level in Firefox, which affects every site you load until you change it for that individual page. In the search bar, about:preferences, scroll down to Default Zoom, and you can either set the total zoom level or just the text on the page as you choose. But the root problem may be different. Is this display resolution only in Firefox, or does if affect everything? If it's only Firefox, set the default zoom level. If it's everything, adjust the DPI settings for the desktop, whichever environment you're using.

[pccobbler]

Thanks to everyone who responded.

The below took me days to figure out. I had a few wild goose chases.

I was running Devuan 2.0 (ASCII) which had an old Cinnamon. A few weeks ago, Firefox ESR started to act very differently than it did before. Everything was zoomed-in about 20%, even though the zoom indicator read 100%. Changing the zoom was not global, in other words, I was forced to change the zoom to 80% for each page I visited, a real PITA.

I thought my old Devuan needed to be replaced. So I wiped the drive and installed Devuan 3.0 (Beowulf). However, the same resize problem was present. cor-el in Mozilla forums suggested that I modify layout.css.devPixelsPerPx. Changing layout.css.devPixelsPerPx to 0.0 made things better, but still not back to what it was before.

I used spare drives to install a few different distributions including Devuan and Linux Mint (regular and LMDE). All of the Cinnamons had the same problem. Then I had an epiphany. I changed LargeText to false -- did I neglect to mention that I always set LargeText to true? -- and Firefox returned to normal, after a restart of it.

So the latest versions of Firefox, both regular and ESR, have an interaction problem with Cinnamon's LargeText setting which did not exist before. I'm not going to get involved in fingerpointing, but I will recommend that users not use LargeText in Cinnamon and set each font manually. If I was getting paid for this, I'd investigate if LargeText in GNOME has the same problem (I'll bet it does).