Dear Apple Developer Support,
We are currently developing a system that requires the ability to edit Japanese vertical text within the Safari browser on iPhone. During our investigation, we encountered an issue that matches the following WebKit bug:
283620 – Caret Positioning Issues in Vertical Writing Mode We understand that this issue is being addressed in the following pull request: https://github.com/WebKit/WebKit/pull/39939 However, it appears that a complete fix has not yet been implemented.
Given this situation, we would like to confirm the following:
Is there any known workaround for this issue in iOS 17.5 or iOS 18.5 (the latest versions as of now)? If a workaround exists, could you please provide details? If not, could you share the expected timeline for a full resolution of this issue? Although this appears to be an open-source WebKit issue, we are reaching out to Apple because WebKit is tightly integrated with iOS and Safari, and ultimately delivered as part of the iPhone experience.
Thank you very much for your support.
Best regards, Takao Kurabayashi