small fixes

[vincentvanhees]

Three very small issue fixes that do not affect functionality:

Fixes #1064 Fixes #1060 Fixes #1055

None of these require mentioning in the changelog.

Checklist before merging:

• [ ] Existing tests still work (check by running the test suite, e.g. from RStudio).
• [ ] Added tests (if you added functionality) or fixed existing test (if you fixed a bug).
• [ ] Updated or expanded the documentation.
• [ ] Updated release notes in inst/NEWS.Rd with a user-readable summary. Please, include references to relevant issues or PR discussions.
• [ ] Added your name to the contributors lists in the DESCRIPTION file, if you think you made a significant contribution.