[previews] Previews text is blank or black, when some characters are present

[David Callé]

While testing the markup limitations of the Description field of previews, I've noticed that some characters made the field blank or completely black. I've not yet identified these characters.

Screenshots attached.

[Nick Dedekind (nick-dedekind)]

If you are able to attach the file which causes the black background, that would be great.

[David Callé (davidc3)]

I'm guessing that the black background is in fact really related to the amount of text (but probably the amount of lines, not characters). Some texts cause a black background when the Dash is windowed, but works fine when it's fullscreen. Others cause it in both cases.

I'm attaching two texts, one not working only in windowed Dash and one failing on both.

[Nick Dedekind (nick-dedekind)]

I'm presuming the attached files is the description, not the content of the preview files?

I think this may be related to LP#1039020
The fix for this is in https://code.launchpad.net/~nick-dedekind/unity/lp1039020.preview-text-escape.

[David Callé (davidc3)]

Sorry, that wasn't clear. Yes, it's the description field.

[David Callé (davidc3)]

I've just tested the fix for LP#1039020 and it doesn't seem to fix this bug.
I'm still trying to identify the exact cause.

[David Callé (davidc3)]

Hi Nick , I've hacked a lens dedicated to this debug and I have some data:
- A blank description can be triggered by the presence of unrecognized tags in the text such as <a>,<ul>,<li>, etc.
- A black description can be triggered when the text is longer than 454 lines (and by that, I don't mean the number of \n or \r characters, but the visible number of preview text lines).

[Stephen M. Webb (bregma)]

Much of this software has been rewritten over the last couple of cycles, and the descriptions sounds like a know fixed bug.

Is this problem still reproduceable with the current Unity 7 software?

[Launchpad Janitor (janitor)]

[Expired for Unity because there has been no activity for 60 days.]