1462457 - Newest update May 17, 2018 completely screws up reading my webpage

Status: RESOLVED DUPLICATE of bug 1460917

(Core :: Security: Process Sandboxing, defect)

Description

[msd]

Attachment: Screen Shot 2018-05-17 at 4.23.21 PM.png

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:60.0) Gecko/20100101 Firefox/60.0
Build ID: 20180516032328

Steps to reproduce:

I didn't do anything, you did it. The automatic update today "Quantum" screws up reading my webpage. Yikes. Look at pix.



Expected results:

My webpage should render properly

Comment 1

[Gingerbread Man]

Please take the following steps then report the results:

1. Right-click (or Ctrl+click) one of the many [A] symbols and choose "Inspect Element (Q)".
2. In the top right corner of the developer tools pane that opened, click the Fonts tab.
3. What's listed at the top of that section, above "Other fonts in page"?

1. Enter the following into the address bar:
about:config?filter=security.sandbox.content.level
2. When the warning appears, click the big button to bypass it.
3. On the next page, double-click the security.sandbox.content.level entry. In the box that pops up, type 1 then press the OK button.
4. Quit, then restart Firefox. Does the problem still occur?


My suspicion is that the results are "Last Resort" and the problem goes away, which would make this a duplicate of bug 1460917.

Comment 2

[msd]

From: Maggi Smith-Dalton/SSM  


Thank you . I followed your steps and the problem did indeed go away. And you were correct. The results did show “Last Resort.”
I’d like to understand why it happened and what changing that number did to fix it in case I need to redesign the webpage. Is this bug exclusive to this version of Firefox, does it affect others’ view of my webpage if they use Firefox, or is it something I need to be aware of next time I use the web design software I rely on (Everweb).
If these questions aren’t too much to answer, I’d appreciate it!

Blessings and thank you very much
Maggi


On May 17, 2018, at 6:42 PM, Bugzilla@Mozilla <[e-mail]> wrote:


Bug 1462457: Newest update May 17, 2018 completely screws up reading my webpage
https://bugzilla.mozilla.org/show_bug.cgi?id=1462457
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--- Comment #1 
Please take the following steps then report the results:

1. Right-click (or Ctrl+click) one of the many [A] symbols and choose "Inspect
Element (Q)".
2. In the top right corner of the developer tools pane that opened, click the
Fonts tab.
3. What's listed at the top of that section, above "Other fonts in page"?

1. Enter the following into the address bar:
about:config?filter=security.sandbox.content.level
2. When the warning appears, click the big button to bypass it.
3. On the next page, double-click the security.sandbox.content.level entry. In
the box that pops up, type 1 then press the OK button.
4. Quit, then restart Firefox. Does the problem still occur?


My suspicion is that the results are "Last Resort" and the problem goes away,
which would make this a duplicate of bug 1460917.

Comment 3

[Gingerbread Man]

Thank you for the update.

There are two issues. Here's the style applied to one of the p elements of class Style4:
font-family: "CooperBT-Bold", "Cooper Lt BT"

1. You have the specified fonts installed in a non-standard location, possibly as a result of using a font manager application. That means Firefox's security sandbox doesn't allow them to be loaded. This is a problem that cropped up in Firefox 60 and was resolved in Firefox 61, which is slated for release June 26. The aforementioned about:config preference lowers the security sandbox level, allowing fonts from non-standard locations to load. This is considered safe enough to use as a temporary workaround.

2. Normally font CSS declarations are supposed to end with a generic font family, like serif, sans-serif, or monospace [1]. This would apply the user's default font of that type, when the page's specified font isn't available. Since you don't do this, Last Resort ends up being applied, rather than something readable.

As an additional note, if you want to ensure visitors see the same font as you, downloadable fonts [2] are the way to go.

[1] https://developer.mozilla.org/en-US/docs/Learn/CSS/Styling_text/Fundamentals#Font_stacks
[2] https://css-tricks.com/snippets/css/using-font-face/

Comment 4

[Haik Aftandilian [:haik]]

(In reply to Gingerbread Man from comment #3)
> 1. You have the specified fonts installed in a non-standard location,
> possibly as a result of using a font manager application. That means
> Firefox's security sandbox doesn't allow them to be loaded. This is a
> problem that cropped up in Firefox 60 and was resolved in Firefox 61, which
> is slated for release June 26.

We are planning to uplift the fix for this problem to Firefox 60 and get this fixed prior to June 26. If you'd like to try build 61 temporarily, that is the current version of Firefox Beta which is available for download[1].

1. https://www.mozilla.org/en-US/firefox/channel/desktop/