check-config: look for ui.configwith We previously weren't looking for this config helper. And, surprise, profiling.py references config options without docs. If I tried hard enough, I could have combined the regexps using a positive lookbehind assertion or something. But I didn't want to make my brain explode. At some point, we should probably do this linting at the tokenizer or ast layer. I'm not willing to open that can of worms right now.

check-config: use named groups in regexp In preparation for making this regexp a bit more complicated.

check-config: use compiled regexp And split the regexp across multiple lines to make it easier to read.

tests: add test coverage for check-config We didn't have explicit test coverage before. I broke check-config.py as part of writing patches and was lucky I realized it.

exchange: use context manager for bundle1 unbundling The lazy locking is not used for bundle1, so using a regular context manager is clearer.

unbundle: use context manager for transaction

clonebundle: use context managers for lock and transaction