yaakovschectman deaf9cc98c Use start instead of extent for Windows IME cursor position (flutter/engine#45667)
When composing with the IME in a text edit, we should add the `start` of
the composition range to the in-composition `cursor_pos` rather than its
`extent`. When using `extent`, the cursor position would always be
outside of the composition range, resulting in the linked bug. Add a
test to check cursor position.

https://github.com/flutter/flutter/issues/123749

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2023-09-13 16:17:48 -04:00
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