Bug 62854 – Vertical text in ruby element is not rendered properly if writing-mode is set dynamically

• Status: NEW
• Component: Layout and Rendering

[Ryosuke Niwa]

Open the url (Simple RTE shows you a scary XSS warning but you can trust me :))  Vertical text isn't rendered properly.

[Ryosuke Niwa]

Created attachment 97578 [details]
reduction

Here's a reduction.  The key is to wrap the contents by ruby element and set -webkit-writing-mode in script.  WebKit then does not render vertical text properly.

[Ryosuke Niwa]

I'd say this is a major loss of function since I can't read the text.

[Ryosuke Niwa]

Created attachment 97644 [details]
correct rendering

[Denis Nomiyama (dnomi)]

Created attachment 159154 [details]
Proposed patch for FreeType fonts

I have tested this issue against the GTK with FreeType port, and I have noticed that both test contents (dynamic -webkit-writing-mode or not) don't work properly on this port.
Mainly because texts are rotated 90 degrees, which make difficult to read. I have also noticed this problem is not only related to ruby elements but all CJK texts displayed with vertical-rl.
I have been working on a fix for GTK/FreeType port and it would be great if someone could have a look at it.

Please let me know if it would be better to raise a new bug report for this patch as this one is more related to dynamic -webkit-writing-mode.

Many thanks.

[Julien Chaffraix]

Comment on attachment 159154 [details]
Proposed patch for FreeType fonts

View in context: https://bugs.webkit.org/attachment.cgi?id=159154&action=review

Thanks for the patch. r-'ing the patch because it's on the wrong bug, I don't know FreeType so I haven't looked at the change.

> Source/WebCore/ChangeLog:4
> +        [Layout and Rendering] This fix rotates CJK characters -90 degrees when using -webkit-writing-mode as vertical-rl.
> +        This fix is only applied to FreeType font.

It's not good practice to hijack a bug to post your patch. This patch has *nothing* to do with the original bug (which is as you mentioned is specific to ruby) and should be attached on its own bug.

Also you should use the bug title in your ChangeLog, not another name: if the bug title doesn't match what you want, change it to match the underlying bug.

If you are unsure about the bugzilla etiquette, free free to check with people on #webkit.

[Denis Nomiyama (dnomi)]

My apologies for attaching a patch to the wrong bug report.
I didn't realize there was already a bug for it. The patch has been attached to Bug 50619.