Bug 94410 - fast/writing-mode/vertical-baseline-alignment.html has wrong expected png
Summary: fast/writing-mode/vertical-baseline-alignment.html has wrong expected png
Status: NEW
Alias: None
Product: WebKit
Classification: Unclassified
Component: Text (show other bugs)
Version: 528+ (Nightly build)
Hardware: All All
: P2 Normal
Assignee: Nobody
URL:
Keywords:
Depends on: 51450
Blocks:
  Show dependency treegraph
 
Reported: 2012-08-17 21:00 PDT by Koji Ishii
Modified: 2019-03-22 04:01 PDT (History)
2 users (show)

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Description Koji Ishii 2012-08-17 21:00:24 PDT
The two expected files:
LayoutTests/platform/chromium-linux/fast/writing-mode/vertical-baseline-alignment-expected.png
LayoutTests/platform/chromium-win/fast/writing-mode/vertical-baseline-alignment-expected.png

has Japanese text aligned to Latin baseline, while:

LayoutTests/platform/mac/fast/writing-mode/vertical-baseline-alignment-expected.png

has Japanese and English text aligned at centeral.

According to the spec, baseline alignment must be central in vertical flow:
http://dev.w3.org/csswg/css3-writing-modes/#text-baselines
Comment 1 Koji Ishii 2012-08-27 05:27:12 PDT
After discussed with fantasai, I removed [chromium] prefix from the summary.

It was found originally during the fix for bug 51450 where Chromium aligned Japanese text with English text using baseline, but then the expected image for Mac:
http://trac.webkit.org/browser/trunk/LayoutTests/platform/mac/fast/writing-mode/vertical-baseline-alignment-expected.png
turned out to be wrong in terms of "SHOULD NOT BE CENTERED" span should actually be centered according to the spec.

The current code has two issues:
1. It changes alignment by fonts; Chromium Win issue went away by applying "MS Gothic". The spec defines dominant baseline is central in vertical flow regardless of the font.
2. Even Latin inlines should be centered when dominant baseline is central. The expected image above is wrong in this regard.

#2 might look strange to Latin users, but Latin vertical flow should use text-orientation:sideways, which makes dominant baseline to alphabetic as per spec:
http://dev.w3.org/csswg/css3-writing-modes/#text-baselines
Comment 2 Manuel Rego Casasnovas 2019-03-22 04:01:26 PDT
(In reply to Koji Ishii from comment #1)
> 2. Even Latin inlines should be centered when dominant baseline is central.
> The expected image above is wrong in this regard.
> 
> #2 might look strange to Latin users, but Latin vertical flow should use
> text-orientation:sideways, which makes dominant baseline to alphabetic as
> per spec:
> http://dev.w3.org/csswg/css3-writing-modes/#text-baselines

This is somehow related to the lack of support for "text-orientation: sideways", see bug #196139.