Robert Knight

> Here "flow" uses a single char ligature, whereas the text returned from PDF.js's text extraction APIs uses separate "f" and "l" characters. To summarize the issue for future reference:...

> Position of highlights is not updated after changing zoom level This may be fixed by https://github.com/hypothesis/client/pull/7019.

> 2. Position of highlights is not updated after changing zoom level > 3. Clicking on annotations doesn't select them in the sidebar, although creating a selection that includes an...

> A new issue that has appeared is that thumbnail rendering doesn't work in the latest PDF.js version. This feature expands the surface area of PDF.js APIs that we interact...

> The [supported browser range](https://github.com/mozilla/pdf.js/wiki/Frequently-Asked-Questions#legacy-build) for the "legacy" build changed. As of May 2025 it requires Safari 16.4 (Mar 2023) and Chrome 110 (Feb 2023) The minimum browser versions listed...

Summarizing the status of the issues that were identified: > 1. Mismatch of Unicode normalization between text returned by text extraction APIs and text layer. There may also be mismatches...

The Unicode normalization issue was solved by https://github.com/hypothesis/client/pull/7123. A this point Hypothesis is now compatible with the current versions of PDF.js. When we come to update the viewer in Via,...

The integration with Epub.js and Readium is non-functional and needs to be re-implemented from scratch along the lines of the VitalSource integration. See also https://github.com/hypothesis/client/issues/4283 and https://github.com/hypothesis/client/issues/4153. We have removed...

We currently use the `unload` event to: 1. Detect when a guest window is unloaded and send a "close" message via the MessagePort. See https://github.com/hypothesis/client/blob/30112b6268f88c44556b53d7494ae3e7b0981e23/src/shared/messaging/port-rpc.ts#L245 2. Detect when a same-origin...

Related to this, we could also potentially optimize thumbnail rendering by only rendering a thumbnail once per highlight group.