Based on https://github.com/zendframework/zend-form/releases/tag/release-2.12.1 (commit 8d985c5ed745317509dc9e68a437417a24fbea2f in this repo)

Added
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- Nothing.

Changed
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- Nothing.

Deprecated
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- Nothing.

Removed
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- Nothing.

Fixed
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- [zendframework/zend-form#218](https://github.com/zendframework/zend-form/pull/218) ensures object values of select elements can be rendered without error.

- [zendframework/zend-form#216](https://github.com/zendframework/zend-form/pull/216) fixes an issue when performing data binding and a fieldset has no mapped
  input elements, casting `null` values to empty arrays to ensure they can be
  passed to an input filter.

- [zendframework/zend-form#207](https://github.com/zendframework/zend-form/pull/207) fixes the return value annotation for the `Fieldset::get()` method to
  indicate it can also return a `FieldsetInterface` instance.