[Android] Extra characters deleted when selecting word and typing

[elliotdavies]

When selecting a word and typing to replace it, too many characters are deleted. Specifically, the selected word is deleted and then the same number of characters are deleted again.

I've only observed this when using the Android virtual keyboard (on a Samsung Galaxy Tab S9).

Steps to reproduce

• Type a few words into Quill e.g. This is some text
• Select a word e.g. some
• Type a letter e.g. y
• Expected result: This is y text (y was inserted and the 4 characters of some were deleted)
• Actual result: This is yt (y was inserted and 8 characters were deleted)

Screen_Recording_20251028_145808_Samsung.Internet.mp4

Cause

It seems that Quill emits the .delete delta twice, once when the IME composition begins and once when it ends. (The Android virtual keyboard is considered an IME.)

• When the composition begins Quill emits .retain(8).delete(4)
• When the composition ends Quill emits .retain(8).insert("y").delete(4) <-- this .delete should not be here