Fix textAlign start/end for placement: line

[ahocevar]

Fixes #14930

[github-actions]

📦 Preview the website for this branch here: https://deploy-preview-14932--ol-site.netlify.app/.

[jahow]

The change in this PR looks good but I'm confused because the image currently on main seems correct: "small text" is at the start of the line and "negative offset X" is at the end.

Am I missing something?

[ahocevar]

The image in main is correct, but a failing test in #14923 revealed the problem, which was unnoticed because the change was below the image tolerance threshold.

[ahocevar]

@jahow Now that #14923 is merged, I rebased this pull request and you can see the change in the diff of the reference image.

[jahow]

@jahow Now that #14923 is merged, I rebased this pull request and you can see the change in the diff of the reference image.

Ok yes, I understand, the image on main wasn't what the actual result looked like! But now doesn't that mean that this PR will significantly change the behavior for the textAlign property on lines? I mean, if that regression was there for a while, maybe people inverted end and start values in their application?

[ahocevar]

start and end is useful for applications that mix left-to-right and right-to-left text. I don't think there are many using that for aligning text along lines, otherwise someone would have created a bug report.

To avoid such regressions in the future, I lowered the test tolerance.

[ahocevar]

I was wrong in assuming that this was a regression. The failed attempt to get left-to-right/right-to-left detection right was #11722, and that simply failed to fix the problem for text alignment along lines. So it was still broken after #11722, and is now fixed.

[ahocevar]

@jahow Were you suggesting to add a note about this in the release notes, or do you not agree with the fix in its entirety?

[jahow]

Yes a mention of this in the release notes wouldn't hurt I guess! Thanks for the fix and taking the time to make sense of all this :)