Fix bug with task name as substring of task name.

[hjoliver]

These changes close #3664

Requirements check-list

• I have read CONTRIBUTING.md and added my name as a Code Contributor.
• Contains logically grouped changes (else tidy your branch by rebase).
• Does not contain off-topic changes (use other PRs for other changes).
• Applied any dependency changes to both setup.py and conda-environment.yml.
• Appropriate tests are included (unit and/or functional).
• Appropriate change log entry included.
• No documentation update required.

[kinow]

Tested on master and got a strange xbool.

['bool(self.satisfied[("foo", "1", "succeeded")])', 'xbool(self.satisfied[("foo", "1", "succeeded")])']

Switched to this branch, and now got the correct result as per doctests.

['bool(self.satisfied[("foo", "1", "succeeded")])', 'bool(self.satisfied[("xfoo", "1", "succeeded")])']

Minor comment, but looks good to me! Thanks @hjoliver

[hjoliver]

Tested on master and got a strange xfoo.

I think you pasted the wrong line there? The error case should have xbool in it, due to a bad string replacement.

[kinow]

Tested on master and got a strange xfoo.

I think you pasted the wrong line there? The error case should have xbool in it, due to a bad string replacement.

Ops, copied from the wrong section from the terminal output, fixed! Thanks.

[dwsutherland]

Reproduced bug on master, couldn't on this branch 👍