Pressing backspace in empty document crashes tab in Vanadium

push-f.com commented

2026-05-08 05:30:02 +02:00

Vanadium is a security hardened fork of Chromium used on GrapheneOS (an Android-based OS) as the System WebView, so e.g. regular Chrome on GrapheneOS also uses the Vanadium WebView. Pressing backspace in a CodeMirror 6 editor with an empty document crashes the tab in Vanadium. I reported this to Vanadium. Interestingly it also happens in Monaco (though different from CM6, there it already happens when pressing backspace in an empty line).

I'd love to have a minimal reproduction example for the Vanadium bug report that doesn't rely on CodeMirror but I've not managed to produce one yet ... just the CodeMirror contenteditable HTML doesn't do it, so it must be related to some JS code. Interestingly it also happens with EditorState.readOnly.of(true).

[Vanadium](https://github.com/GrapheneOS/Vanadium) is a security hardened fork of Chromium used on [GrapheneOS](https://grapheneos.org) (an Android-based OS) as the System WebView, so e.g. regular Chrome on GrapheneOS also uses the Vanadium WebView. Pressing backspace in a CodeMirror 6 editor with an empty document crashes the tab in Vanadium. I [reported this to Vanadium](https://github.com/GrapheneOS/Vanadium/issues/1118). Interestingly it also happens in Monaco (though different from CM6, there it already happens when pressing backspace in an empty line). I'd love to have a minimal reproduction example for the Vanadium bug report that doesn't rely on CodeMirror but I've not managed to produce one yet ... just the CodeMirror `contenteditable` HTML doesn't do it, so it must be related to some JS code. Interestingly it also happens with `EditorState.readOnly.of(true)`.

marijn commented

2026-05-08 08:26:48 +02:00

Owner

If I go to https://codemirror.net in Vanadium 148.0.7778.96.0, backspace out the content of the demo editor, and continue backspacing, nothing happens. Any further details on how to reproduce this?

push-f.com commented

2026-05-08 08:31:55 +02:00

Author

Huh, I'm assuming you're also testing this on GrapheneOS? I can reproduce it every time on a Pixel 7a and on a Pixel 9 Pro.

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Pressing backspace in empty document crashes tab in Vanadium #1701