I agree. Tests for bug fixes are extremely valuable. Of such tests, unit tests are often very feasible.

A test accompanying a bug fix holds value in many ways.

Firstly, it demonstrates to those reviewing the change that the fix is suitable.

Secondly, the presence of a test encourages reviewers to consider what a test does and doesn't cover, sometimes resulting in comments regarding improvements that had not otherwise been considered.

Thirdly, and of most importance in the long term, a test for a bug fix serves to document oddities previously discovered that were for a time not known about.