1907209 - Changing default font size does not change font of all message previews

Status: UNCONFIRMED

(Thunderbird :: Message Reader UI, defect)

Description

[Gregory]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:127.0) Gecko/20100101 Firefox/127.0

Steps to reproduce:

I change the default font size setting and disable "allow messages to use other fonts"

Actual results:

Some messages use the new font, but most retain the old font. This is the case with at least the plain text and simple html views.

Original html seemed to work better, but I cannot view some text in this mode at all due to my other configurations.

For using simple html or plain text views - I must keep default size at 16 to ensure consistency between message previews and composer.

Expected results:

The default font size setting should change all the messages, not only a random few.

Comment 1

[tfardet]

I have the same issue with plain text emails having way too small font size in 115.13.0 (20240715172621).
Further more, if I increase the font size via the menu from 16 to 17, the font size in plain text email suddenly jumps to a legible size but it resets every time thunderbird restarts.
This issue is limited to the mail view UI, the composer UI uses proper font sizes.
I have checked all known issues from https://support.mozilla.org/en-US/kb/thunderbird-115-supernova-faq#w_why-are-thunderbird-115s-fonts-so-large-so-small

Comment 2

[Nicolas Mandil (:NicolasWeb)]

Dupe of bug 1854607 ?

Comment 3

[Anje]

If you have an issue with the font size then ask a question in the Thunderbird Support Forum and then post a link to that question so I can take a look. This is not a Support Forum.

My experience comes from helping people in the Support Forum - when it comes to Font Size the user does not fully understand how to set up the requirements they prefer. I've sorted out a lot of cases. Most cases involve incorrect settings causing conflict or not all settings have been set up.

Basic info below.

1. Menu app icon > Font Size
   default is 12px
   Increasing font size effects everything in ui - eg: Menu, Folder Pane, Message List etc
   But can be overruled in Message Pane and composing - see info below in 2 and 3
   Some computers use 4K resolution which forces a pixel to a very small size and can cause an issue. This sometimes manifests as a Font Size 7px in Thunderbird and can only be reset via Config Editor resetting the preference 'mail.uifontsize' pixel size to 12. Thus making the Font Size functional again.

2. Settings > General
   Under 'Languages & Appearance'
   Click on 'Advanced'
   This is where you set up what you regard as 'medium' font size.
   The minimum font size should always be a bit smaller or same size as proportion and monospace font size - never larger otherwise it overrules a lot of settings.
   You must set up the same settings for 'Fonts for' - 'Latin' and 'Other Writing Systems' because 'Latin' sets up for Western encoding and 'Other Writing Systems' sets up for Unicode encoding. If you only set up for eg: Latin you may find emails using unicode encoding appear a difference size. In addition set up for any other font type you use.
   Disable "allow messages to use other fonts" can control the actual font.

3. Settings > Composition
   Advise you use the default font size = Medium and this will use whatever font size has been set up in number 2 above.
   It also means no code is enforced on the recipient, so whatever the recipient uses as 'medium' will be used.

4. The Config Editor preference 'layout.css.devPixelsPerPx' previously used to effect overall pixel size - it is now advised that you leave this with it's default negative number -1.0 Otherwise it can conflict with the newer parts of design for Font Size control.

Comment 4

[Anje]

(In reply to tfardet from comment #1)

I have the same issue with plain text emails having way too small font size in 115.13.0 (20240715172621).
Further more, if I increase the font size via the menu from 16 to 17, the font size in plain text email suddenly jumps to a legible size but it resets every time thunderbird restarts.
This issue is limited to the mail view UI, the composer UI uses proper font sizes.
I have checked all known issues from https://support.mozilla.org/en-US/kb/thunderbird-115-supernova-faq#w_why-are-thunderbird-115s-fonts-so-large-so-small

Anything you set which is lost when the session is closed implies the 'prefs.js' file is not being updated.
Please check both 'Latin' and 'Other Writing Systems' (and any other you use) have been set up to be identical.
If you use any program that can cleanup files eg: CCLeaner, WiseCleaner or even some Anti-Virus products other a clean up of files - those programs may be deleting the session data or preventing updates to files.
Make your thunderbird profile exempt from scanning etc.

Please ask a question in the Thunderbird Support Forum on this issue to see if someone can help.

Comment 5

[tfardet]

Please check both 'Latin' and 'Other Writing Systems' (and any other you use) have been set up to be identical.

Setting the monospace size for 'Other Writing Systems' to 16 seems to solve the issue for the plaintext emails.
I'm not sure why that happens, though, is UTF-8 encoding considered "other writing system" and is latin refering to the actual encoding? (that would seem rather strange).

Is there a specific reason why the monospace font is so small compare to the other ones? Why not set it to the same size as the others? This would effectively prevent this issue as all other fonts had already moved to 16.

Anyway, thanks for the tip, it would be very useful to have this displayed prominently somewhere if the underlying issue cannot be fixed for some reason.